Best_IPv6 Routing Operation

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Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Table of Contents

Huawei Technologies Proprietary

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Table of Contents

Chapter 1 IPv6 Static Routing Configuration ............................................................................. 1-1 1.1 Introduction to IPv6 Static Routing .................................................................................... 1-1

1.1.1 Features and Functionalities of IPv6 Static Routes ................................................ 1-1 1.1.2 Default IPv6 Route .................................................................................................. 1-1

1.2 Configuring IPv6 Static Routes.......................................................................................... 1-2 1.2.1 Configuration prerequisites ..................................................................................... 1-2 1.2.2 Configuring IPv6 Static Routes............................................................................... 1-2

1.3 Displaying and Maintaining IPv6 Static Routes ................................................................. 1-2 1.4 IPv6 Static Routing Configuration Example....................................................................... 1-3

Chapter 2 IPv6-RIPng Configuration........................................................................................... 2-1 2.1 Introduction to RIPng ......................................................................................................... 2-1

2.1.1 RIPng Working Mechanism..................................................................................... 2-1 2.1.2 RIPng Packet Format.............................................................................................. 2-2 2.1.3 RIPng Packet Processing Procedure...................................................................... 2-3 2.1.4 Protocol Specification.............................................................................................. 2-4

2.2 RIPng Basic Configuration................................................................................................. 2-4 2.2.1 Configuration Prerequisites..................................................................................... 2-4 2.2.2 Configuring the Basic RIPng Function.................................................................... 2-4

2.3 RIPng Configuration .......................................................................................................... 2-5 2.3.1 Configuring an Additional Routing Metric................................................................ 2-5 2.3.2 Configuring RIPng Route Summarization............................................................... 2-5 2.3.3 Configuring RIPng to Advertise a Default Route..................................................... 2-6 2.3.4 Configuring a RIPng Route Filtering Policy............................................................. 2-6 2.3.5 Configuring a RIPng Priority.................................................................................... 2-7 2.3.6 Configuring RIPng Route Redistribution................................................................. 2-7

2.4 RIPng Network Adjustment and Optimization ................................................................... 2-8 2.4.1 Configuring RIPng Timers....................................................................................... 2-8 2.4.2 Configuring the Split Horizon and Poison Reverse Functions................................ 2-8 2.4.3 Configuring Zero Field Check for RIPng Packet Headers ...................................... 2-9 2.4.4 Configuring the Maximum Number of Equivalent Routes..................................... 2-10

2.5 Displaying and Maintaining RIPng................................................................................... 2-10 2.6 RIPng Configuration Example ......................................................................................... 2-10

Chapter 3 IPv6-OSPFv3 Configuration........................................................................................ 3-1 3.1 Introduction to OSPFv3 ..................................................................................................... 3-1

3.1.1 OSPFv3 Overview................................................................................................... 3-1 3.1.2 OSPFv3 Packets..................................................................................................... 3-1 3.1.3 OSPFv3 LSA Types ................................................................................................ 3-2





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3.1.4 Timers of OSPFv3................................................................................................... 3-3 3.1.5 OSPFv3 Features Supported.................................................................................. 3-3 3.1.6 Related RFCs.......................................................................................................... 3-3

3.2 IPv6-OSPFv3 Configuration Task List ............................................................................... 3-4

3.3 Configuring OSPFv3 Basic Functions ............................................................................... 3-4 3.3.1 Prerequisites ........................................................................................................... 3-4 3.3.2 Configuring OSPFv3 Basic Functions..................................................................... 3-4

3.4 Configuring OSPFv3 Area Parameters ............................................................................. 3-5 3.4.1 Prerequisites ........................................................................................................... 3-5 3.4.2 Configuring an OSPFv3 Stub Area......................................................................... 3-5 3.4.3 Configuring OSPFv3 Virtual Links........................................................................... 3-6

3.5 Configuring OSPFv3 Routing Information Management ................................................... 3-7 3.5.1 Prerequisites ........................................................................................................... 3-7 3.5.2 Configuring OSPFv3 Route Summarization ........................................................... 3-7 3.5.3 Configuring OSPFv3 Inbound Route Filtering......................................................... 3-7 3.5.4 Configuring Link Costs for OSPFv3 Interfaces ....................................................... 3-8 3.5.5 Configuring the Maximum Number of OSPFv3 Load-balancing Routes ................ 3-8 3.5.6 Configuring OSPFv3 Route Redistribution ............................................................. 3-9

3.6 Configuring OSPFv3 Network Optimization ...................................................................... 3-9 3.6.1 Prerequisites ......................................................................................................... 3-10 3.6.2 Configuring OSPFv3 Timers ................................................................................. 3-10 3.6.3 Configuring the DR Priority for an Interface .......................................................... 3-11 3.6.4 Ignoring MTU Check for DD Packets.................................................................... 3-11 3.6.5 Disable Interfaces from Sending OSPFv3 Packets .............................................. 3-12

3.7 Displaying and Maintaining OSPFv3 ............................................................................... 3-13 3.8 OSPFv3 Configuration Examples.................................................................................... 3-14

3.8.1 Configuring OSPFv3 Areas................................................................................... 3-14 3.8.2 Configuring OSPFv3 DR Election ......................................................................... 3-18

3.9 Troubleshooting OSPFv3 Configuration.......................................................................... 3-21 3.9.1 No OSPFv3 Neighbor Relationship Established................................................... 3-21 3.9.2 Incorrect Routing Information................................................................................ 3-22

Chapter 4 IPv6-IS-IS Configuration.............................................................................................. 4-1 4.1 Introduction to IPv6-IS-IS................................................................................................... 4-1 4.2 IPv6-IS-IS Basic Configuration .......................................................................................... 4-1

4.2.1 Configuration Prerequisites..................................................................................... 4-2 4.2.2 Configuring IPv6-IS-IS Basic Functions.................................................................. 4-2

4.3 Configuring IPv6-IS-IS Routing Information Control.......................................................... 4-2 4.3.1 Configuration Prerequisites..................................................................................... 4-2 4.3.2 Configuration Procedure ......................................................................................... 4-2

4.4 Displaying and Maintaining IPv6-IS-IS .............................................................................. 4-4 4.5 IPv6-IS-IS Configuration Example ..................................................................................... 4-4





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Chapter 5 IPv6-BGP4+ Configuration.......................................................................................... 5-1 5.1 BGP4+ Overview ............................................................................................................... 5-1 5.2 Configuration Task List ...................................................................................................... 5-2 5.3 Configuring BGP4+ Basic Functions ................................................................................. 5-3

5.3.1 Prerequisites ........................................................................................................... 5-3 5.3.2 Configuring an IPv6 Peer........................................................................................ 5-3 5.3.3 Advertising a Local IPv6 Route ............................................................................... 5-3 5.3.4 Configuring a Preferred Value for Routes Received from a Peer/Peer Group ....... 5-4 5.3.5 Specifying a Local Update Source Interface to a Peer/Peer Group ....................... 5-4 5.3.6 Configuring a Non Direct EBGP Connection to a Peer/Peer Group....................... 5-5 5.3.7 Configuring Description for a Peer/Peer Group ...................................................... 5-5 5.3.8 Establishing No Session to a Peer/Peer Group...................................................... 5-6 5.3.9 Logging Session State and Event Information of a Peer/Peer Group .................... 5-6

5.4 Controlling Route Distribution and Reception.................................................................... 5-7 5.4.1 Prerequisites ........................................................................................................... 5-7 5.4.2 Configuring BGP4+ Route Redistribution ............................................................... 5-7 5.4.3 Advertising Default Route to a Peer/Peer Group.................................................... 5-8 5.4.4 Configuring Route Distribution Policy...................................................................... 5-8 5.4.5 Configuring Route Reception Policy ....................................................................... 5-9 5.4.6 Configuring BGP4+ and IGP Route Synchronization ........................................... 5-10 5.4.7 Configuring Route Dampening.............................................................................. 5-11

5.5 Configuring BGP4+ Route Attributes............................................................................... 5-11 5.5.1 Prerequisites ......................................................................................................... 5-11 5.5.2 Configuring BGP4+ Preference and Default LOCAL_PREF and NEXT_HOP

Attributes ........................................................................................................................ 5-11 5.5.3 Configuring the MED Attribute .............................................................................. 5-12 5.5.4 Configuring the AS_PATH Attribute...................................................................... 5-13

5.6 Adjusting and Optimizing BGP4+ Networks.................................................................... 5-13 5.6.1 Prerequisites ......................................................................................................... 5-14 5.6.2 Configuring BGP4+ Timers ................................................................................... 5-14 5.6.3 Configuring BGP4+ Soft Reset ............................................................................. 5-15 5.6.4 Configuring the Maximum Number of Load-Balancing Routes............................. 5-16

5.7 Configuring a Large Scale BGP4+ Network .................................................................... 5-17 5.7.1 Prerequisites ......................................................................................................... 5-17 5.7.2 Configuring BGP4+ Peer Group ........................................................................... 5-17 5.7.3 Configuring BGP4+ Community............................................................................5-19 5.7.4 Configuring a BGP4+ Router Reflector................................................................. 5-20

5.8 Displaying and Maintaining BGP4+ Configuration .......................................................... 5-21 5.8.1 Displaying BGP ..................................................................................................... 5-21 5.8.2 Resetting BGP4+ Connections ............................................................................. 5-22 5.8.3 Clearing BGP4+ Information ................................................................................. 5-22

5.9 BGP4+ Configuration Examples...................................................................................... 5-23





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5.9.1 BGP4+ Basic Configuration .................................................................................. 5-23 5.9.2 BGP4+ Router Reflector Configuration................................................................. 5-25

5.10 Troubleshooting BGP4+ Configuration.......................................................................... 5-27 5.10.1 No BGP4+ Peer Relationship Established.......................................................... 5-27

Chapter 6 Routing Policy Configuration..................................................................................... 6-1

6.1 Introduction to Routing Policy ............................................................................................ 6-1 6.1.1 Routing Policy and Policy Routing.......................................................................... 6-1 6.1.2 Filters....................................................................................................................... 6-1 6.1.3 Routing Policy Application....................................................................................... 6-3

6.2 Defining Filtering Lists ....................................................................................................... 6-3 6.2.1 Prerequisites ........................................................................................................... 6-3 6.2.2 Defining an IPv6-prefix List ..................................................................................... 6-3 6.2.3 Defining an AS Path ACL........................................................................................ 6-4 6.2.4 Defining a Community List ...................................................................................... 6-4

6.3 Configuring a Routing Policy ............................................................................................. 6-4 6.3.1 Prerequisites ........................................................................................................... 6-5 6.3.2 Creating a Routing Policy........................................................................................ 6-5 6.3.3 Defining if-match Clauses for the Routing Policy.................................................... 6-6 6.3.4 Defining apply Clauses for the Routing Policy ........................................................ 6-7

6.4 Displaying and Maintaining the Routing Policy.................................................................. 6-8 6.5 Routing Policy Configuration Example .............................................................................. 6-9

6.5.1 Applying Routing Policy When Redistributing IPv6 Routes.................................... 6-9 6.6 Troubleshooting Routing Policy Configuration ................................................................ 6-10

6.6.1 IPv6 Routing Information Filtering Failed.............................................................. 6-10



Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 1 IPv6 Static Routing Configuration


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Chapter 1 IPv6 Static Routing Configuration

Note:

The term “router” and router icon in this document refer to either a router in a generic

sense or a Layer 3 switch running routing protocols.

Verify that the system already operates in IPv4/IPv6 dual-stack mode before

configuring IPv6 routing.

All the IPv6 routing related configuration mentioned in this manual assumes that the

system already operates in IPv4/IPv6 dual-stack mode. For dual stack mode

configuration, see the part covering dual stack in the IPv6 Configuration module.

For a manually established tunnel, routing protocols can be employed on the tunnel

interfaces successfully if the tunnel is configured to support expedite termination

subnet addresses. While for tunnels of other types, routing protocols cannot be

employed on the tunnel interfaces successfully.

1.1 Introduction to IPv6 Static Routing

Static routes are special routes that are manually configured by network administrators.

These manually configured static routes work well in simple networks. Configuring and

using them properly can improve the performance of networks and can guarantee

enough bandwidth reserved for important applications.

However, static routes also have their downside: network failure or topology changes

could introduce unreachable routes that lead to network disconnection. Such scenarios

require the network administrators to manually configure and modify the static routes.

1.1.1 Features and Functionalities of IPv6 Static Routes

Similar to IPv4 static routes, IPv6 static routes work well in simple IPv6 network

environments.

Their major difference lies in the destination and the next hop addresses. IPv6 static

routes use IPv6 addresses whereas IPv4 static routes use IPv4 addresses.

1.1.2 Default IPv6 Route

An IPv6 static route that has the destination address configured as “::/0” (indicating a

prefix length of 0) is the default IPv6 route. If the destination address of an IPv6 packet





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does not match any entries in the routing table, this default route will be used to forward

the packet.

1.2 Configuring IPv6 Static RoutesIn small IPv6 network environments, IPv6 static routes can be used to achieve network

connectivity. In comparison to dynamic routes, it helps to save network bandwidth.

1.2.1 Configuration prerequisites

Enabling IPv6 packet forwarding

Ensuring that the neighboring nodes are IPv6 reachable

1.2.2 Configuring IPv6 Static Routes

To do… Use the commands… Remarks

Enter system view system-view —

Configure an IPv6static route

ipv6 route-static ipv6-address prefix-length [ interface-type interface-number ]nexthop-address [ preference preference-value ]

Required;

The default preference ofIPv6 static routes is 60..

1.3 Displaying and Maintaining IPv6 Static Routes

To do… Use the command… Remarks

Display IPv6 staticroute information

display ipv6 routing-table protocol static [ inactive |verbose ]

Available in any view

Remove all IPv6static routes

delete ipv6 static-routes all Available in system view

Note:

Using the undo ipv6 route-static command deletes a single IPv6 static route, while

using the delete ipv6 static-routes all command deletes all IPv6 static routes

including the default route.





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1.4 IPv6 Static Routing Configuration Example

I. Network requirements

With IPv6 static routes configured, all hosts and switches can interact with each other.

II. Network diagram

PC11::2/64

SwitchA

SwitchB

SwitchC

Vlan-interface1001::1/64




PC22::2/64

PC33::2/64




Figure 1-1 Network diagram for static routes

III. Configuration procedure

1) Configure the IPv6 addresses of all VLAN interfaces (Omitted here)

2) Configure IPv6 static routes.

# Configure on SwitchA the default IPv6 static route.

<SwitchA> system-view

[SwitchA] ipv6

[SwitchA] ipv6 route-static :: 0 4::2

# Configure two IPv6 static routes on SwitchB.

<SwitchB> system-view

[SwitchB] ipv6

[SwitchB] ipv6 route-static 1:: 64 4::1

[SwitchB] ipv6 route-static 3:: 64 5::1

# Configure on SwitchC the default IPv6 static route.

<SwitchC> system-view

[SwitchC] ipv6

[SwitchC] ipv6 route-static :: 0 5::2

3) Configure the IPv6 addresses of hosts and gateways.

Configure the IPv6 addresses of all the hosts based upon the network diagram,

configure the default gateway of PC1 as 1::1, PC2 as 2::1, and PC3 as 3::1.

4) Display configuration information





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# Display the IPv6 routing table of SwitchA.

[SwitchA] display ipv6 routing-table

Routing Table :

Destinations : 7 Routes : 7

Destination: ::/0 Protocol : Static

NextHop : 4::2 Preference: 60

Interface : Vlan200 Cost : 0

Destination: ::1/128 Protocol : Direct

NextHop : ::1 Preference: 0

Interface : InLoop0 Cost : 0

Destination: 1::/64 Protocol : Direct

NextHop : 1::1 Preference: 0

Interface : Vlan100 Cost : 0

Destination: 1::1/128 Protocol : Direct



Destination: 4::/64 Protocol : Direct

NextHop : 4::1 Preference: 0Interface : Vlan200 Cost : 0

Destination: 4::1/128 Protocol : Direct



Destination: FE80::/10 Protocol : Direct

NextHop : :: Preference: 0

Interface : NULL0 Cost : 0

# Verify with the ping command.

[SwitchA] ping ipv6 3::1

PING 3::1 : 56 data bytes, press CTRL_C to break

Reply from 3::1

bytes=56 Sequence=1 hop limit=63 time = 5 ms

Reply from 3::1


Reply from 3::1


Reply from 3::1





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Reply from 3::1


--- 3::1 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 4/4/5 ms



Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 2 IPv6-RIPng Configuration


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Chapter 2 IPv6-RIPng Configuration

Note:








2.1 Introduction to RIPng

RIP next generation (RIPng) is an extension of RIP-2 for IPv4. Most RIP concepts are

applicable in RIPng.

To adopt RIPng for IPv6 network, the following modifications have been made on basis

of RIP:

UDP port number: RIPng uses UDP port 521 for sending and receiving routing

information.

Multicast address: RIPng uses FF02:9 as the link-local multicast address.

Destination Prefix: 128-bit destination address prefix.

Next hop: IPv6 address in 128-bit.

Source address: RIPng uses FE80::/10 as the link-local source address

2.1.1 RIPng Working Mechanism

RIPng is a routing protocol based on the distance vector (D-V) algorithm. RIPng uses

UDP packets to exchange routing information through port 521.

RIPng uses a hop count to measure the distance to the destination. The hop count is

referred to as metric or cost. The hop count from a router to the network that the router

is directly connected is 0. The hop count from one router to another router is 1, and so

on. When the hop count is greater than or equal to 16, the destination network or host is

unreachable.

By default, the routing update is sent every 30 seconds. If the router cannot receive

routing updates within 180 seconds, the routes learnt from neighbors are considered as





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fail. After another 240 seconds, if no routing updates are received, the router will

remove those routes from the routing table.

RIPng supports Split Horizon and Poison Reverse to prevent routing loops, and route

redistribution.

Each RIPng router maintains a routing database, including route entries to all

reachable destinations. These route entries contain the following information:

Destination address: IPv6 address of a host or a network.

Next hop address: IP address of a neighbor router along the path to the

destination.

Egress interface: Interface that forwards IPv6 packets.

Metric: Cost from the local router to the destination.

Routing time: Time elapsed since the routing entry is updated last time. Routing

time is reset to 0 each time the routing entry is updated. Route tag: It is used for tagging external routes so that the routes can be controlled

flexibly in routing policy based on the tags.

2.1.2 RIPng Packet Format

I. Basic format

A RIPng packet consists of a header and multiple route table entries (RTEs). For a

RIPng packet, the maximum number of RTEs is related to the MTU of the sending

interface.

Figure 2-1 shows the basic packet format of RIPng.

0 7 15 31

command must be zeroversion

Route Table Entry N (20 octets)

Route Table Entry 1 (20 octets)

Figure 2-1 RIPng basic packet format

Command: Type of message. 0x01 indicates Request, 0x02 indicates Response.

Version: Version of RIPng. It can only be 0x01 for the moment.

RTE: Route table entry, 20 bytes for each entry.

II. RTE format

There are two types of RTE in RIPng.

Next hop RTE: Defines a next hop IPv6 address

IPv6 prefix RTE: Describes the destination IPv6 address and metric in the RIPng

routing table.





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Figure 2-2 shows format of the next hop RTE

0 7 15 31

must be zero must be zero 0xFF

IPv6 next hop address (16 octets)

Figure 2-2 Next hop RTE format

IPv6 next hop address is the IPv6 address of the next hop.

Figure 2-3 shows the format of the IPv6 prefix RTE.

0 7 15 31

IPv6 prefix (16 octets)

route tag prefix len metric

Figure 2-3 IPv6 prefix RTE format

IPv6 prefix: Destination IPv6 address prefix.

Route tag: Intended to differentiate internal RIP routes from external RIP routes.

Prefix len: Length of the IPv6 address prefix. Metric: Cost of a route.

2.1.3 RIPng Packet Processing Procedure

I. Request packet

When a RIPng router first starts or needs to update part entries in its routing table, the

request packet is sent as multicast to ask for routing information from neighbors.

The requested RIPng router processes the received request based on the RTE. If there

is only one RTE, and IPv6 prefix and the prefix length is 0 with a metric value of 16, therequested RIPng router will response with the entire routing table. If there are multiple

RTEs in a Request message, the requested RIPng router will examine each RTE,

update its metric, and send the requested routing information to the requesting router in

the response packet.

II. Response packet

The response packet containing the local routing table information is generated under

the following conditions:

Response to a specific request

Update sent periodically





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Trigged update caused by route changes

Before the router updates its RIPng routing table based on the received response, it

must check the validation of the response packet, such as whether the IPv6 address is

the link-local address, whether the port number is correct. The response packet failedthe check will be discarded.

2.1.4 Protocol Specification

RIPng related specifications are:

RFC2080: RIPng for IPv6

RFC2081: RIPng Protocol Applicability Statement

RFC2453: RIP Version 2

2.2 RIPng Basic Configuration

In this section, you are presented with the information to configure the basic RIPng

features.

In the configurations, RIPng should be enabled first. But it is not necessary for RIPng

related interface configurations, such as assigning an IPv6 address.

2.2.1 Configuration Prerequisites

Before the configuration, accomplish the following tasks first:

Enable IPv6 packet forwarding.

Configure IP address on each interface, and make sure all nodes are reachable.

2.2.2 Configuring the Basic RIPng Function

Follow these steps to configure the basic RIPng function:


Enter system view system-view ––

Create a RIPng process

and enter RIPng view ripng [ process-id ] Required

Not created by default

Return to system view quit —

Enter interface viewinterface interface-type interface-number

––

Enable RIPng on aspecified interface ripng process-id enable

Required

Disabled by default





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Note:

If RIPng is not enabled on an interface, the interface will not send and receive any

RIPng route.

2.3 RIPng Configuration


Configure IP address on each interface, and make sure all nodes are reachable.

Configure RIPng basic functions

Define an IPv6 ACL before using it for route filtering. Refer to ACL configuration for

related information.

Define the IPv6 address prefix list before using it for route filtering. Refer to 6.2

Defining Filtering Lists

2.3.1 Configuring an Additional Routing Metric

Additional routing metric is an input/output metric added to a RIPng route, including

additional metric of sent routes and additional metric of received routes.

The additional metric of a sent route will not change the routing metric in the routing

table and will be added only when an interface sends RIPng routing information.

The additional metric of a received route will change the routing metric in the routing

table. When an interface receives a valid RIP route, the additional metric will be added

to the route before the route is added to the routing table

Follow these steps to configure the RIPng priority and additional routing metric:




––

Define an additionalrouting metric forreceived routes

ripng metricin value Optional

0 by default

Define an additionalrouting metric foradvertised routes ripng metricout value Optional

1 by default

2.3.2 Configuring RIPng Route Summarization

Follow these steps to configure RIPng route summarization





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Enter interface view interface interface-type interface-number ––

Advertise a summaryIPv6 prefix ripng summary-address ipv6-address

prefix-length Required

2.3.3 Configuring RIPng to Advertise a Default Route

Follow these steps to configure RIPng default route:




––

Configure RIPng toadvertise a defaultroute

ripng default-route { only | originate } [ cost value ]

Required

By default, RIPng does notadvertise any default route.

Note:

The RIPng default route is forced to send in the update message of the designated

interface regardless of whether it exists in the IPv6 routing table.

2.3.4 Configuring a RIPng Route Filtering Policy

You can filter received routing information based on IPv6 ACL or IPv6 prefix list. Only

those routes that are not filtered will be added to the RIPng routing table. In addition,

you can filter routes to be advertised by the local host, including RIPng routes

redistributed from other routing protocols or learned from neighbors. Only routes that

satisfy the conditions will be advertised to RIPng neighbors.

Follow these steps to configure a RIPng route filtering policy:



Enter RIPng view ripng [ process-id ] ––

Define a filtering policy forreceived routinginformation

filter-policy { acl6-number |ipv6-prefix ipv6-prefix-name }

import

Required

By default, RIPng doesnot filter received routing

information.





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Define a filtering policy for

routing information to beadvertised

filter-policy{ acl6-number |

ipv6-prefix ipv6-prefix-name } export [ protocol [ process-id ] ]

Required

By default, RIPng does

not filter routinginformation to beadvertised.

2.3.5 Configuring a RIPng Priority

Any routing protocol has its own specific protocol priority. The device can select an

optimal route from different protocol routes. You can set a priority for RIPng manually.

The smaller the value is, the higher the priority is.

Follow these steps to configure a RIPng priority:



Enter RIPng view ripng [ process-id ] —

Configure a RIPng prioritypreference [ route-policy route-policy-name ] value

Optional

By default, the value ofthe RIPng priority is 100.

2.3.6 Configuring RIPng Route Redistribution

Follow these steps to configure RIPng redistributed route:




Configure a defaultrouting metric for a

redistributed route

default cost value

Optional

By default, the default

metric of a redistributeroute is 0.

Redistribute a route

import-route protocol [ process-id ][ allow-ibgp ] [ cost cost-value | route-policyroute-policy-name ] *

Required

By default, RIPng doesnot redistribute any otherprotocol route.





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2.4 RIPng Network Adjustment and Optimization

This section describes how to adjust and optimize the performance of the RIPng

network as well as applications under special network environments. Before adjusting

and optimizing the RIPng network, complete the following tasks:

Configure a network layer address for an interface

Configure the basic RIPng function

2.4.1 Configuring RIPng Timers

You can adjust RIPng timers to optimize the performance of the RIPng network.

Follow these steps to configure RIPng timers:



Enter RIPng view ripng [ process-id ] —

Configure RIPngtimers

timers{ garbage-collectgarbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value }

*

Optional.

The RIPng timers have thefollowing defaults:

30 seconds for the update timer

180 seconds for the timeouttimer

120 seconds for the suppress

timer 240 seconds for the

garbage-collect timer

Note:

When adjusting RIPng timers, you should consider the network performance and

perform unified configurations on routers running RIPng to avoid unnecessary network

traffic increase or route oscillation.

2.4.2 Configuring the Split Horizon and Poison Reverse Functions

Note:

If both the split horizon and poison reverse functions are configured, only the poison

reverse function takes effect.





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I. Configure the split horizon function

The split horizon function disables a route learned from an interface from being

advertised so as to prevent a routing loop between neighbor routers.

Follow these steps to configure the split horizon function:




––

Enable the split horizonfunction ripng split-horizon Optional

Enabled by default

Note:

Normally you are recommended to enable the split horizon to prevent routing loops.

II. Configuring the poison reverse function

The poison reverse function enables a route learned from an interface to be advertised.

However, the metric of the route is set to 16. That is to say, the route is unreachable

Follow these steps to configure poison reverse:




––

Enable the poison reversefunction ripng poison-reverse Required

Disabled by default

2.4.3 Configuring Zero Field Check for RIPng Packet Headers

Some fields in RIPng packet headers must be zero. These fields are called zero fields.

You can enable the zero field check for RIPng packet headers. If any such field contains

a non-zero value, the entire RIPng packet will not be processed. If you are sure that all

packets are trusty, you can disable the zero field check to save the CPU processing

time.

Follow these steps to configure RIPng zero field check:





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Enable the zero fieldcheck for RIPng packerheaders checkzero Optional

Enabled by default

2.4.4 Configuring the Maximum Number of Equivalent Routes

Follow these steps to configure the maximum number of RIPng equivalent routes in

load sharing mode:




Configure the maximumnumber of equivalentroutes in load sharingmode

maximumload-balancing number

Optional

By default, the maximumload-balancing is 4.

2.5 Displaying and Maintaining RIPng


Display configurationinformation of a RIPng process display ripng

[ process-id ] Available in anyview

Display routes in the databaseadvertised by RIPng

display ripng process-id database

Available in anyview

Display routing information ofthe specified RIPng process

display ripng process-id route


Display information of a RIPnginterface

display ripng process-id interface [ interface-type interface-number ]


2.6 RIPng Configuration Example


As shown in Figure 2-4, all switches run RIPng. Configure Switch B to filter the route

(3::/64) learnt from Switch C, which means the route will not be added to the routing

table of Switch B, and Switch B will not forward it to Switch A.





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II. Network diagram

SwitchA SwitchB SwitchC

RIPng

1::2/64

1::1/64

3::1/64 3::2/64


5::1/64

2::1/64 Vlan-interface100

Vlan-interface100 Vlan-interface200

Vlan-interface200

Vlan-interface400

Vlan-interface500

SwitchA SwitchB SwitchC

RIPng

1::2/64

1::1/64

3::1/64 3::2/64


5::1/64

2::1/64 Vlan-interface100

Vlan-interface100 Vlan-interface200

Vlan-interface200

Vlan-interface400

Vlan-interface500

Figure 2-4 Network diagram for RIPng configuration


1) Configure the IPv6 address for each interface

Omitted

2) Configure basic RIPng function

# Configure Switch A.


[SwitchA] ipv6

[SwitchA] ripng 1

[SwitchA-ripng-1] quit

[SwitchA] interface vlan-interface 100

[SwitchA-Vlan-interface100] ripng 1 enable

[SwitchA-Vlan-interface100] quit




# Configure Switch B.


[SwitchB] ipv6

[SwitchB] ripng 1

[SwitchB-ripng-1] quit

[SwitchB] interface vlan-interface 200

[SwitchB-Vlan-interface200] ripng 1 enable

[SwitchB-Vlan-interface200] quit




# Configure Switch C.





2-12


[SwitchC] ipv6

[SwitchC] ripng 1

[SwitchC-ripng-1] quit

[SwitchC] interface vlan-interface 200

[SwitchC-Vlan-interface200] ripng 1 enable

[SwitchC-Vlan-interface200] quit







# Display routing table of Switch B.

<SwitchB> display ripng 1 route

Route Flags: A - Aging, S - Suppressed, G - Garbage-collect

----------------------------------------------------------------

Peer FE80::20F:E2FF:FE23:82F5 on Vlan-interface100

Dest 1::/64,

via FE80::20F:E2FF:FE23:82F5, cost 1, tag 0, A, 6 Sec

Dest 2::/64,


Peer FE80::20F:E2FF:FE00:100 on Vlan-interface200

Dest 3::/64,

via FE80::20F:E2FF:FE00:100, cost 1, tag 0, A, 11 Sec

Dest 4::/64,


Dest 5::/64,


# Display the routing table of Switch A.

[SwitchA] display ripng 1 route


----------------------------------------------------------------

Peer FE80::200:2FF:FE64:8904 on Vlan-interface100

Dest 1::/64,

via FE80::200:2FF:FE64:8904, cost 1, tag 0, A, 31 Sec

Dest 4::/64,






2-13

Dest 5::/64,


Dest 3::/64,


3) Configure Switch B to filter received routes

[SwitchB] acl ipv6 number 2000

[SwitchB-acl6-basic-2000] rule deny source 3::/64

[SwitchB-acl6-basic-2000] rule permit

[SwitchB-acl6-basic-2000] quit

[SwitchB] ripng 1

[SwitchB-ripng-1] filter-policy 2000 import

[SwitchB-ripng-1] filter-policy 2000 export

[SwitchB-ripng-1] quit

# Display routing tables of Switch B and Switch A.

[SwitchB] display ripng 1 route


----------------------------------------------------------------

Peer FE80::20F:E2FF:FE23:82F5 on Vlan-interface100

Dest 1::/64,


Dest 2::/64,



Dest 4::/64,


Dest 5::/64,


[SwitchA] display ripng 1 route


----------------------------------------------------------------


Dest 1::/64,


Dest 4::/64,


Dest 5::/64,




Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 3 IPv6-OSPFv3 Configuration


3-1

Chapter 3 IPv6-OSPFv3 Configuration

Note:








3.1 Introduction to OSPFv3

3.1.1 OSPFv3 Overview

OSPFv3 is OSPF (Open Shortest Path First) version 3 for short, supporting IPv6 and

compliant with RFC2740 (OSPF for IPv6).

Unchanged parts between OSPFv3 and OSPFv2:

32 bits router ID and area ID

Packets: Hello, DD (Data Description), LSR (Link State Request), LSU (Link State

Update), LSAck (Link State Acknowledgment)

Mechanisms for finding neighbors and establishing adjacencies

Mechanisms for LSA flooding and aging

Differences between OSPFv3 and OSPFv2:

OSPFv3 now runs on a per-link basis, instead of on a per-IP-subnet basis.

OSPFv3 supports multiple instances per link. OSPFv3 identifies neighbors by Router IDs, while OSPFv2 by IP addresses.

3.1.2 OSPFv3 Packets

OSPFv3 has also five types of packets: hello, DD, LSR, LSU, and LSAck.

The five packets have the same packet header, which different from the OSPFv2

packet header is only 16 bytes in length, has no authentication field, but added with an

Instance ID field to support multi-instance per link.

Figure 3-1 gives the OSPFv3 packet header.





3-2

Version # Type Packet Length

Router ID

Area ID

Checksum

0

Instance ID 0

3115

Figure 3-1 OSPFv3 packet header

Major fields:

Version #: Version of OSPF, which is 3 for OSPFv3.

Type: Type of OSPF packet, from 1 to 5 are hello, DD, LSR, LSU, and LSAckrespectively.

Packet Length: Packet length in bytes, including header.

Instance ID: Instance ID for a link.

0: Reserved, which must be 0.

3.1.3 OSPFv3 LSA Types

OSPFv3 sends routing information in LSAs, which as defined in RFC2740 have the

following types:

Router-LSAs: Originated by all routers. This LSA describes the collected states ofthe router's interfaces to an area. Flooded throughout a single area only.

Network-LSAs: Originated for broadcast and NBMA networks by the Designated

Router. This LSA contains the list of routers connected to the network. Flooded

throughout a single area only.

Inter-Area-Prefix-LSAs: Similar to Type 3 LSA of OSPFv2, originated by ABRs

(Area Border Routers), and flooded throughout the LSA's associated area. Each

Inter-Area-Prefix-LSA describes a route with IPv6 address prefix to a destination

outside the area, yet still inside the AS (an inter-area route).

Inter-Area-Router-LSAs: Similar to Type 4 LSA of OSPFv2, originated by ABRs

and flooded throughout the LSA's associated area. Each Inter-Area-Router-LSA

describes a route to ASBR (Autonomous System Boundary Router).

AS-external-LSAs: Originated by ASBRs, and flooded throughout the AS (except

Stub and NSSA areas). Each AS-external-LSA describes a route to another

Autonomous System. A default route can be described by an AS external LSA.

Link-LSAs: A router originates a separate Link-LSA for each attached link.

Link-LSAs have link-local flooding scope. Each Link-LSA describes the IPv6

address prefix of the link and Link-local address of the router,

Intra-Area-Prefix-LSAs: Each Intra-Area-Prefix-LSA contains IPv6 prefix

information on a router, stub area or transit area information, and has area





3-3

flooding scope. It was introduced because Router-LSAs and Network-LSAs

contain no address information now.

3.1.4 Timers of OSPFv3

Timers in OSPFv3 include:

OSPFv3 packet timer

LSA delay timer

SPF timer

I. OSPFv3 packet timer

Hello packets are sent periodically between neighboring routers for finding and

maintaining neighbor relationships, or for DR/BDR election. The hello interval must be

identical on neighboring interfaces. The smaller the hello interval, the faster thenetwork convergence speed and the bigger the network load.

If a router receives no hello packet from a neighbor after a period, it will declare the peer

is down. The period is called dead interval.

After sending an LSA to its adjacency, a router waits for an acknowledgment from the

adjacency. If no response received after retransmission interval elapses, the router will

send again the LSA. The retransmission interval must be longer than the round-trip

time in between.

II. LSA delay time

Each LSA has an age in the local LSDB (incremented by 1 per second), but an LSA is

not aged on transmission. You need to add an LSA delay time into the age time before

transmission, which is important for low speed networks.

III. SPF timer

Whenever LSDB changes, SPF recalculation happens. If recalculations become so

frequent, a large amount of resources will be occupied, reducing operation efficiency of

routers. You can adjust SPF calculation interval and delay time to protect networks from

being overloaded due to frequent changes.

3.1.5 OSPFv3 Features Supported

Basic features defined in RFC2740

OSPFv3 stub area

OSPFv3 multi-process, which enable a router to run multiple OSPFv3 processes

3.1.6 Related RFCs

RFC2740: OSPF for IPv6

RFC2328: OSPF Version 2





3-4

3.2 IPv6-OSPFv3 Configuration Task List

To configure OSPFv3, perform the tasks described in the following sections:

Task Description

Configuring OSPFv3 Basic Functions Required

Configuring an OSPFv3 Stub Area OptionalConfiguring OSPFv3 Area Parameters Configuring OSPFv3 Virtual Links Optional

Configuring OSPFv3 Route Summarization

Optional

Configuring OSPFv3 Inbound RouteFiltering

Optional

Configuring Link Costs for OSPFv3Interfaces Optional

Configuring the Maximum Number ofOSPFv3 Load-balancing Routes

Optional

Configuring OSPFv3

Routing Information Management

Configuring OSPFv3 Route Redistribution

Optional

Configuring OSPFv3 Timers Optional

Configuring the DR Priority for anInterface

Optional

Ignoring MTU Check for DD Packets Optional

Configuring OSPFv3 Network Optimization

Disable Interfaces from Sending OSPFv3 Packets

Optional

3.3 Configuring OSPFv3 Basic Functions

3.3.1 Prerequisites

Make neighboring nodes accessible with each other at network layer.

Enable IPv6 packet forwarding

3.3.2 Configuring OSPFv3 Basic Functions

To configure OSPFv3 basic functions, use the following commands:



Enable OSPFv3 andenter its view

ospfv3 [ process-id ] Required

Specify a router ID router-id router-id Required





3-5



—

Enable OSPFv3 on theinterface

ospfv3 process-id areaarea-id [ instanceinstance-id ]

Required

Not enabled by default

Note:

Configure an OSPFv3 process ID when enabling OSPFv3. The process ID takes

effect locally, without affecting packet exchange between routers.

When configuring a router ID, make sure each router has a unique ID. If a router

runs multiple OSPFv3 processes, you need to specify a router ID for each process.

You need to specify a router ID manually, which is necessary to make OSPFv3

work.

3.4 Configuring OSPFv3 Area Parameters

The stub area and virtual link support of OSPFv3 has the same principle and

application environments with OSPFv2.

Splitting an OSPFv3 AS into multiple areas reduces the number of LSAs on networksand extends OSPFv3 application. For those non-backbone areas residing on the AS

boundary, you can configure them as Stub areas to further reduce the size of routing

tables on routers in these areas and the number of LSAs.

Non-backbone areas exchange routing information via the backbone area. Therefore,

the backbone and non-backbone areas, including the backbone itself must maintain

connectivity. In practice, necessary physical links may not be available for connectivity.

You can configure virtual links to address it.

3.4.1 Prerequisites


Configure OSPFv3 basic functions

3.4.2 Configuring an OSPFv3 Stub Area

To configure an OSPFv3 stub area, use the following commands:



Enter OSPFv3 view ospfv3 [ process-id ] Required





3-6


Enter OSPFv3 area view area area-id Required

Configure the area as astub area stub [ no-summary ]

Required

Not configured by default

Configure the defaultroute cost of sending apacket to the stub area

default-cost value Optional

Defaults to 1

Note:

Configurations on routers attached to the same area should be compatible to avoid

information exchange failures even information block and routing loop.

You cannot delete an OSPFv3 area directly. Only when you remove allconfigurations in area view and all interfaces attached to the area become down,

can the area be removed automatically.

All routers attached to a stub area must be configured with the stub command. The

keyword no-summary is only available on the ABR.

If you use the stub command with the keyword no-summary on an ABR, the ABR

distributes a default summary LSA into the area rather than generating an

AS-external-LSA or Inter-Area-Prefix-LSA. The stub area of this kind is also known

as totally stub area.

3.4.3 Configuring OSPFv3 Virtual Links

You can configure virtual links to maintain connectivity between non-backbone areas

and the backbone, or in the backbone itself.

To configure a virtual link, use the following commands:





Create and configure avirtual link

vlink-peer router-id [ hello seconds | retransmit seconds |trans-delay seconds | dead seconds | instance instance-id ] *

Required





3-7

Note:

Both ends of a virtual link are ABRs that are configured with the vlink-peer command.

3.5 Configuring OSPFv3 Routing Information Management

This section is to configure management of OSPF routing information advertisement

and reception, and route redistribution from other protocols.

3.5.1 Prerequisites



3.5.2 Configuring OSPFv3 Route Summarization

To configure route summarization between areas, use the following command on a

ABR:





Configure a summaryroute

abr-summary ipv6-address prefix-length [ not-advertise ]

Required


Note:

The abr-summary command is available on ABRs only. If contiguous network

segments are available in an area, you can use the command to summarize them into

one network segment on the ABR. The ABR will advertise only the summary route. AnyLSA falling into the specified network segment will not be advertised, reducing the

LSDB size in other areas.

3.5.3 Configuring OSPFv3 Inbound Route Filtering

You can configure OSPFv3 to filter routes that are computed from received LSAs

according to some rules.

To configure inbound route filtering, use the following commands:





3-8




Configure inbound routefiltering

filter-policy { acl6-number |ipv6-prefix ipv6-prefix-name } import

Required


Note:

Use of the filter-policy import command can only filter routes computed by OSPFv3.

Only routes not filtered can be added into the local routing table.

3.5.4 Configuring Link Costs for OSPFv3 Interfaces

You can configure OSPFv3 link costs for interfaces to adjust routing calculation.

To configure the link cost for an OSPFv3 interface, use the following commands:



Enter interface view interface interface-type interface-number —

Configure the cost for theinterface

ospfv3 cost value [ instance instance-id ]

Optional

By default, The costvalue defaults to 1.

3.5.5 Configuring the Maximum Number of OSPFv3 Load-balancing Routes

If multiple routes to a destination are available, using load balancing to send IPv6

packets on these routes in turn can improve link utility. To configure the maximum

number of load-balancing routes, use the following commands:




Specify the maximumnumber of load-balancingroutes

maximumload-balancing maximum

Optional

By default, the maximumnumber of load-balancingroutes supported by

OSPFv3 is four





3-9

3.5.6 Configuring OSPFv3 Route Redistribution

To configure OSPFv3 route redistribution, use the following commands:




Specify a default cost forredistributed routes

default cost value Optional

Defaults to 1

Redistribute routes fromother protocols, includingfrom other OSPFv3

processes

import-route { isisv6process-id | ospfv3 process-id | ripng process-id | bgp4+[ allow-ibgp ] | direct | static }[ cost value | type type |

route-policyroute-policy-name ] *

Required

Not configured bydefault

Configure to filterredistributed routes

filter-policy { acl6-number |ipv6-prefix ipv6-prefix-name }export [ isisv6 process-id | ospfv3 process-id | ripng process-id | bgp4+ | direct | static]

Optional


Note:

Using the import-route command on a router makes the router become an ASBR.

Since OSPFv3 is a link state based routing protocol, it cannot directly filter LSAs to

be advertised. Therefore, you need to configure filtering redistributed routes before

advertising routes that are not filtered in LSAs into the routing domain.

Use of the filter-policy export command takes effect only on the local router.

However, if the import-route command is not configured, executing the

filter-policy export command does not take effect.

3.6 Configuring OSPFv3 Network Optimization

This section describes configurations of OSPFv3 timers, interface DR priority, MTU

check ignorance for DD packets, disabling interfaces from sending OSPFv3 packets.

OSPFv3 timers:

Packet timer: Specified to adjust topology convergence speed and network load

LSA delay timer: Specified especially for low speed links

SPF timer: Specified to protect networks from being over consumed due to

frequent network changes.





3-10

For a broadcast network, you can configure DR priorities for interfaces to affect

DR/BDR election.

By disabling an interface from sending OSPFv3 packets, you can make other routers

on the network obtain no information from the interface.

3.6.1 Prerequisites



3.6.2 Configuring OSPFv3 Timers

To configure OSPFv3 timers, use the following commands:




Configure hello intervalospfv3 timer hello seconds [ instanceinstance-id ]

Optional

Defaults to 10 seconds.

Configure dead intervalospfv3 timer dead seconds [ instanceinstance-id ]

Optional

Defaults to 40 seconds.

Configure LSAretransmission interval

ospfv3 timer retransmitinterval [ instanceinstance-id ]

Optional

Defaults to 5 seconds

Configure LSAtransmission delay

ospfv3 trans-delay seconds [ instanceinstance-id ]

Optional

Defaults to 1 second

Exit to system view quit —


Configure SPF timerspf timers delay-interval hold-interval

Optional

delay-interval defaults to5 seconds;

hold-interval defaults to10 seconds





3-11

Note:

The dead interval set on neighboring interfaces cannot be so small. Otherwise, a

neighbor is so easy to be considered as down.

The LSA retransmission interval cannot be so small to avoid unnecessary

retransmissions.

3.6.3 Configuring the DR Priority for an Interface

To configure the DR priority for an interface, use the following commands:




Configure the DR priorityospfv3 dr-priority priority [ instance instance-id ]

Optional

Defaults to 1

Note:

The DR priority of an interface determines the interface’s qualification in DR election.

Interfaces having the priority 0 cannot become a DR or BDR.

3.6.4 Ignoring MTU Check for DD Packets

When LSAs are few, it is unnecessary to check MTU in DD packets in order to improve

efficiency.

To ignore MTU check for DD packets, use the following commands:

To do… Use the command… RemarksEnter system view system-view —


Ignore MTU check for DDpackets ospfv3 mtu-ignore

[ instance instance-id ] Required

Not ignored by default





3-12

3.6.5 Disable Interfaces from Sending OSPFv3 Packets

To disable interfaces from sending any OSPFv3 packet, use the following commands:


Enter system view system-view -


Disable interfaces fromsending any OSPFv3packet

silent-interface { interface-type interface-number | all }

Required

Not disabled by default

Note:

Multiple processes can disable the same interface from sending OSPFv3 packets.Use of the silent-interface command disables only the interfaces associated with

the current process rather than interfaces associated with other processes.

After an OSPF interface is set to silent, direct routes of the interface can still be

advertised in Intra-Area-Prefix-LSAs via other interfaces, but hello packets for

finding neighbors cannot be advertised, so no neighboring relationship can be

established on the interface, enhancing adaptability of OSPFv3 networking.





3-13

3.7 Displaying and Maintaining OSPFv3


Display OSPFv3debugging stateinformation

display debugging ospfv3

Display OSPFv3 processbrief information

display ospfv3 [ process-id ]

Display OSPFv3 interfaceinformation

display ospfv3 interface [ interface-type interface-number |statistic ]

Display OSPFv3 LSDB

information

display ospfv3 [ process-id ] lsdb[ [ external | inter-prefix | inter-router | intra-prefix | link |

network | router ] [ link-state-id ][ originate-router router-id ] | total ]

Display LSA statistics inOSPFv3 LSDB

display ospfv3 lsdb statistic

Display OSPFv3 neighborinformation

display ospfv3 [ process-id ] [ area area-id ] peer [ [ interface-type interface-number ] [ verbose ] | peer-router-id ]

Display OSPFv3 neighborstatistics

display ospfv3 peer statistic

Display OSPFv3 routingtable information

display ospfv3 [ process-id ]routing [ ipv6-address prefix-length | ipv6-address /prefix-length | abr-routes | asbr-routes | all | statistics ]

Display OSPFv3 areatopology information

display ospfv3 [ process-id ] topology [ area area-id ]

Display OSPFv3 virtuallink information

display ospfv3 [ process-id ] vlink

Display OSPFv3 next hop

information

display ospfv3 [ process-id ]

next-hop

Display OSPFv3 link staterequest list information

display ospfv3 [ process-id ]request-list [ statistics ]

Display OSPFv3 link stateretransmission listinformation

display ospfv3 [ process-id ]retrans-list [ statistics ]

Display OSPFv3 statistics display ospfv3 statistic

Available inany view





3-14

3.8 OSPFv3 Configuration Examples

3.8.1 Configuring OSPFv3 Areas


In Figure 3-2, all switches run OSPFv3. The AS is split into three areas, in which,

Switch B and Switch C act as ABRs to forward routing information between areas.

It is required to configure Area 2 as a stub area, reducing LSAs into the area without

affecting route reachability.

II. Network diagram

SwitchB SwitchC

SwitchD


Vlan-interface1002001::2/64 Vlan-interface400

2001:2::1/64

Vlan-interface4002001:2::2/64

OSPFv3

Area0


SwitchA


OSPFv3Area1


OSPFv3Area2 Stub

Figure 3-2 Network diagram for OSPFv3 area configuration


1) Configure IPv6 addresses for interfaces (omitted)

2) Configure OSPFv3 basic functions



[SwitchA] ipv6[SwitchA] ospfv3

[SwitchA-ospfv3-1] router-id 1.1.1.1

[SwitchA-ospfv3-1] quit


[SwitchA-Vlan-interface300] ospfv3 1 area 1









3-15

# Configure Switch B


[SwitchB] ipv6

[SwitchB] ospfv3

[SwitchB-ospf-1] router-id 2.2.2.2

[SwitchB-ospf-1] quit


[SwitchB-Vlan-interface100] ospfv3 1 area 0





# Configure Switch C<SwitchC> system-view

[SwitchC] ipv6

[SwitchC] ospfv3

[SwitchC-ospfv3-1] router-id 3.3.3.3

[SwitchC-ospfv3-1] quit


[SwitchC-Vlan-interface100] ospfv3 1 area 0





# Configure Switch D

<SwitchD> system-view

[SwitchD] ipv6

[SwitchD] ospfv3

[SwitchD-ospfv3-1] router-id 4.4.4.4

[SwitchD-ospfv3-1] quit

[SwitchD] interface Vlan-interface 400

[SwitchD-Vlan-interface400] ospfv3 1 area 2

[SwitchD-Vlan-interface400] quit

# Display OSPFv3 neighbor information on Switch B.

[SwitchB] display ospfv3 peer

OSPFv3 Area ID 0.0.0.0 (Process 1)

----------------------------------------------------------------------

Neighbor ID Pri State Dead Time Interface Instance ID

3.3.3.3 1 Full/DR 00:00:39 Vlan100 0





3-16


----------------------------------------------------------------------


1.1.1.1 1 Full/Backup 00:00:38 Vlan200 0

# Display OSPFv3 neighbor information on Switch C.

[SwitchC] display ospfv3 peer


----------------------------------------------------------------------


2.2.2.2 1 Full/Backup 00:00:39 Vlan100 0


----------------------------------------------------------------------


4.4.4.4 1 Full/DR 00:00:38 Vlan400 0

# Display OSPFv3 routing table information on Switch D.

[SwitchD] display ospfv3 routing

E1 - Type 1 external route, IA - Inter area route, I - Intra area route

E2 - Type 2 external route, * - Selected route

OSPFv3 Router with ID (4.4.4.4) (Process 1)

------------------------------------------------------------------------

*Destination: 2001::/64

Type : IA Cost : 2

NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400

*Destination: 2001:1::/64

Type : IA Cost : 3



Type : I Cost : 1

NextHop : directly-connected Interface: Vlan400


Type : IA Cost : 4


3) Configure Area 2 as a stub area


[SwitchD] ospfv3





3-17

[SwitchD-ospfv3-1] area 2

[SwitchD-ospfv3-1-area-0.0.0.2] stub

# Configure Switch C, with the default route cost to the stub area being 10.

[SwitchC] ospfv3

[SwitchC-ospfv3-1] area 2

[SwitchC-ospfv3-1-area-0.0.0.2] stub

[SwitchC-ospfv3-1-area-0.0.0.2] default-cost 10

# Display OSPFv3 routing table information on Switch D. You can find a default route is

added, whose cost is the cost of the directly connected route plus the configured cost.





------------------------------------------------------------------------

*Destination: ::/0

Type : IA Cost : 11


*Destination: 2001::/64

Type : IA Cost : 2



Type : IA Cost : 3



Type : I Cost : 1



Type : IA Cost : 4


4) Configure Area 2 as a totally stub area

# Configure Switch C, the ABR, to make Area 2 as a totally stub area.

[SwitchC-ospfv3-1-area-0.0.0.2] stub no-summary

# Display OSPFv3 routing table information on Switch D. You can find route entries are

reduced. All non directly connected routes are removed except the default route.






3-18




------------------------------------------------------------------------

*Destination: ::/0

Type : IA Cost : 11



Type : I Cost : 1


3.8.2 Configuring OSPFv3 DR Election


In Figure 3-3:

The priority of Switch A is 100, the highest priority on the network, so it will be the

DR.

The priority of Switch C is 2, the second highest priority on the network, so it will be

the BDR.

The priority of Switch B is 0, so it cannot become the DR.

RouterD has the default priority 1.

II. Network diagram

SwitchBSwitchA

SwitchD




SwitchC


Figure 3-3 Network diagram for OSPFv3 DR election configuration



2) Configure OSPFv3 basic functions

# Configure Switch A





3-19


[SwitchA] ipv6

[SwitchA] ospfv3

[SwitchA-ospfv3-1] router-id 1.1.1.1

[SwitchA-ospfv3-1] quit




# Configure Switch B


[SwitchB] ipv6

[SwitchB] ospfv3

[SwitchB-ospfv3-1] router-id 2.2.2.2

[SwitchB-ospfv3-1] quit




# Configure Switch C


[SwitchC] ipv6

[SwitchC] ospfv3

[SwitchC-ospfv3-1] router-id 3.3.3.3

[SwitchC-ospfv3-1] quit






[SwitchD] ipv6

[SwitchD] ospfv3

[SwitchD-ospfv3-1] router-id 4.4.4.4

[SwitchD-ospfv3-1] quit

[SwitchD] interface vlan-interface 200

[SwitchD-Vlan-interface200] ospfv3 1 area 0


# Display neighbor information on Switch A. You can find routers have the same default

DR priority 1. In this case, the router with the highest Router ID is elected as the DR, so

Switch D is the DR, Switch C is the BDR.

[SwitchA] display ospfv3 peer






3-20

----------------------------------------------------------------------


2.2.2.2 1 2-Way/DROther 00:00:36 Vlan200 0

3.3.3.3 1 Full/Backup 00:00:35 Vlan100 0

4.4.4.4 1 Full/DR 00:00:33 Vlan200 0

# Display neighbor information on Switch D. You can find neighbor states between

Router D and other routers are all full.

[SwitchD] display ospfv3 peer


----------------------------------------------------------------------


1.1.1.1 1 Full/DROther 00:00:30 Vlan100 0


3.3.3.3 1 Full/Backup 00:00:31 Vlan100 0

3) Configure DR priorities for interfaces.

# Configure the DR priority of Vlan-interface100 as 100 on Switch A.

[SwitchA] interface Vlan-interface 100

[SwitchA-Vlan-interface100] ospfv3 dr-priority 100


# Configure the DR priority of Vlan-interface 200 as 0 on Switch B.


[SwitchB-Vlan-interface200] ospfv3 dr-priority 0


#Configure the DR priority of Switch C as 2.

[SwitchC] interface Vlan-interface 100

[SwitchC-Vlan-interface100] ospfv3 dr-priority 2


# Display neighbor information on Switch A. You can find DR priorities have been

updated, but DR and BDR are not changed.



----------------------------------------------------------------------


2.2.2.2 0 2-Way/DROther 00:00:38 Vlan200 0

3.3.3.3 2 Full/Backup 00:00:32 Vlan100 0

4.4.4.4 1 Full/DR 00:00:36 Vlan200 0

#Display neighbor information on Switch D. You can find Switch D is still the DR.







3-21

----------------------------------------------------------------------




3.3.3.3 2 Full/Backup 00:00:40 Vlan100 0

4) Restart DR/BDR election

# Use the shutdown and undo shutdown commands on interfaces to restart DR/BDR

election (omitted).

# Display neighbor information on Switch A. You can find Switch C becomes the BDR.



----------------------------------------------------------------------



3.3.3.3 2 Full/Backup 00:00:39 Vlan100 0


# Display neighbor information on Switch D. You can find Switch A becomes the DR.



----------------------------------------------------------------------


1.1.1.1 100 Full/DR 00:00:34 Vlan100 02.2.2.2 0 2-Way/DROther 00:00:34 Vlan200 0

3.3.3.3 2 Full/Backup 00:00:32 Vlan100 0

3.9 Troubleshooting OSPFv3 Configuration

3.9.1 No OSPFv3 Neighbor Relationship Established

I. Symptom

No OSPF neighbor relationship can be established.

II. Analysis

If the physical link and lower protocol work well, check OSPF parameters configured on

interfaces. The two neighboring interfaces must have the same parameters, such as

the area ID, network segment and mask, network type. If the network type is broadcast,

at least one interface must have a DR priority higher than 0.

III. Process steps

1) Display neighbor information using the display ospfv3 peer command.





3-22

2) Display OSPFv3 interface information using the display ospfv3 interface

command.

3) Ping the neighbor router’s IP address to check connectivity.

4) Check OSPF timers. The dead interval on an interface must be at least four timesthe hello interval.

5) On a broadcast network, at least one interface must have a DR priority higher than

0.

3.9.2 Incorrect Routing Information

I. Symptom

OSPFv3 cannot find routes to other areas.

II. Analysis

The backbone area must maintain connectivity to all other areas. If a router connects to

more than one area, at least one area must be connected to the backbone. The

backbone cannot be configured as a Stub area.

In a Stub area, all routers cannot receive external routes, and all interfaces connected

to the Stub area must be associated with the Stub area.

III. Process steps

1) Use the display ospfv3 peer command to display OSPFv3 neighbors.

2) Use the display ospfv3 interface command to display OSPFv3 interfaceinformation.

3) Use the display ospfv3 lsdb command to display Link State Database

information to check integrity.

4) Display information about area configuration using the display

current-configuration configuration command. If more than two areas are

configured, at least one area is connected to the backbone.

5) In a Stub area, all routers are configured with the stub command.

6) If a virtual link is configured, use the display ospf vlink command to check the

neighbor state.



Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 4 IPv6-IS-IS Configuration


4-1

Chapter 4 IPv6-IS-IS Configuration

Note:








4.1 Introduction to IPv6-IS-IS

The IS-IS routing protocol (Intermediate System-to-Intermediate System intra-domain

routing information exchange protocol) supports multiple network protocols, including

IPv6. The IS-IS with IPv6 support is called IPv6-IS-IS dynamic routing protocol. The

International Engineer Task Force (IETF) defines the IPv6 protocol for IS-IS in the file

draft-ietf-isis-ipv6-05. Two type-length-values (TLVs) and a new network layer protocol

identifier (NLPID) are added to support IPv6 protocol.

The TLV is a variable field in the link state PDUs (LSP). The two TLVs are:

IPv6 Reachability: Defines the prefix, metric and other information to indicate the

network reachability, with type 236 (0xEC).

IPv6 Interface Address: A corresponding TLV as the IP Interface Address in IPv4,

which transforms the 32 bits IPv4 address to 128 bits IPv6 address.

NLPID is an 8-bit field with a value of 142 (0x8E). If the IS-IS router supports IPv6, the

routing information is advertised with the NLPID.

4.2 IPv6-IS-IS Basic Configuration

Note:

You can implement IPv6 networking through IPv6-IS-IS in IPv6 network environment.





4-2



Enable IPv6 globally Configure IP address on each interface, and make sure all nodes are reachable.

Enable IS-IS

4.2.2 Configuring IPv6-IS-IS Basic Functions

Follow these steps to configure the basic functions of IPv6-IS-IS

To do… Use command to… Remarks


Create an IS-IS processand enter IS-IS view isis [ process-id ] RequiredNot enabled by default

Set the network entityname of the IS-IS process

network-entity net Required


Enable IPv6 in the IS-ISprocess

ipv6 enable Required

Disabled by default Go back to system view quit ––

Enter interface view interface interface-type interface-number ––

Enable IPv6-IS-IS on aspecified interface isis ipv6 enable

[ process-id ] [ silent ] Required

Disabled by default

4.3 Configuring IPv6-IS-IS Routing Information Control


Note:

You need finish basic IPv6-IS-IS configuration before configuring IPv6-IS-IS routing

features.

4.3.2 Configuration Procedure

Follow these steps to configure IPv6-IS-IS routing information control:





4-3

To do… Use command to… Remarks


Enter IS-IS view isis [ process-id ] ––

Define the routingpriority of IPv6-IS-IS

ipv6 preference { route-policyroute-policy-name | preference-value }*

Optional

15 by default

Configure routesummarization ofIPv6-IS-IS

ipv6 summary ipv6-prefix prefix-length [ avoid-feedback |generate_null0_route | [ level-1 | level-1-2 | level-2 ] | tagtag-value ] *

Optional

Disabled by default

Define an IPv6-IS-IS

default route

ipv6 default-route-advertise [ [ level-1 | level-2 | level-1-2 ] |

route-policy route-policy-name ]*

Optional

No IPv6-IS-IS default

route is defined bydefault.

Configure IPv6 IS-ISto filter receivedroutes

ipv6 filter-policy { acl6-number |ipv6-prefix ipv6-prefix-name |route-policy route-policy-name }import

Optional

No filtering policy isdefined by default

Configure IPv6 IS-ISto redistribute routesfrom another routingprotocol

ipv6 import-route protocol [ process-id | allow-ibgp ] [ cost cost-value | [ level-1 | level-2 | level-1-2 ] | route-policyroute-policy-name | tagtag-value ]*

Optional


Define the filteringpolicy forredistributed route

ipv6 filter-policy { acl6-number |ipv6-prefix ipv6-prefix-name |route-policy route-policy-name }export [ protocol process-id ]

Optional

Do not filter theredistributed route bydefault.

Enable route leaking ipv6 import-route isisv6 level-2into level-1 [ filter-policy{ acl6-number | ipv6-prefixipv6-prefix-name | route-policyroute-policy-name } | tagtag-value ]*

Optional

Not enabled bydefault.

Define the maximumnumber of the loadbalance

ipv6 maximum load-balancingnumber

Optional

4 by default

Note:

The ipv6 filter-policy export command, usually used in combination with the ipv6

import-route command, filters the distributed route when advertising it to other routers.

If no protocol parameter is specified, all distributed protocols will be filtered.





4-4

4.4 Displaying and Maintaining IPv6-IS-IS


Display brief informationof IS-IS

display isis brief Available in any view

Display the status of thedebug switch

display isis debug-switchesprocess-id


Display information of theIS-IS enabled interface

display isis interface[ verbose ] [ process-id ]


Display information of theIS-IS license

display isis license Available in any view

Display the LSDB

information

display isis lsdb [ [ l1 | l2 |level-1 | level-2 ] | [ [ lsp-id

lsp-id | lsp-name lspname ] | local | verbose ]* [ process-id ]


Display the IS-IS meshgroup

display isis mesh-group[ process-id ]


Display the mapping tablebetween the host nameand system ID

display isis name-table[ process-id ]


Display information of theIS-IS peer

display isis peer [ verbose ][ process-id ]


Display the IS-IS routinginformation

display isis route ipv6

[ [ level-1 | level-2 ] |verbose ]* [ process-id ]


Display information of theSPF log

display isis spf-log[ process-id ]


Display statisticinformation of the IS-ISprocess

display isis statistics [ level-1 | level-2 | level-1-2 ][ process-id ]


Clear IS-IS configurationdata

reset isis all [ process-id ]Available in userview

Clear the IS-IS data

information of a neighbor

reset isis peer system-id

[ process-id ]

Available in user

view

4.5 IPv6-IS-IS Configuration Example


As shown in Figure 4-1, connect and enable IS-IS over IPv6 on Switch A, Switch B,

Switch C and Switch D within an autonomous system.





4-5

Switch A and Switch B are Level-1 switches, Switch D is Level-2 switch, and Switch C is

a Level-1-2 switch connecting two areas. Switch A, Switch B, Switch C are in area 10,

while Switch D is in area 20.

II. Network diagram

SwitchBL1

SwitchCL1/2

SwitchDL2

Vlan-interfac e3002001:3::1/64

Vlan-interfac e300

2001:3::2/64



SwitchAL1

IS-ISArea10


IS-ISArea20



SwitchBL1

SwitchCL1/2

SwitchDL2


Vlan-interfac e300

2001:3::2/64



SwitchAL1

IS-ISArea10


IS-ISArea20



Figure 4-1 Network diagram for IPv6-IS-IS basic configuration


1) Configure IPv6 address for each interface

Omitted

2) Configure basic IPv6-IS-IS functions



[SwitchA] isis 1

[SwitchA-isis-1] is-level level-1

[SwitchA-isis-1] network-entity 10.0000.0000.0001.00

[SwitchA-isis-1] ipv6 enable

[SwitchA-isis-1] quit


[SwitchA-Vlan-interface100] isis ipv6 enable 1




[SwitchB] isis 1

[SwitchB-isis-1] is-level level-1

[SwitchB-isis-1] network-entity 10.0000.0000.0002.00

[SwitchB-isis-1] ipv6 enable

[SwitchB-isis-1] quit






4-6

[SwitchB-Vlan-interface200] isis ipv6 enable 1




[SwitchC] isis 1

[SwitchC-isis-1] network-entity 10.0000.0000.0003.00

[SwitchC-isis-1] ipv6 enable

[SwitchC-isis-1] quit


[SwitchC-Vlan-interface100] isis ipv6 enable 1








# Configure Switch D.


[SwitchD] isis 1

[SwitchD-isis-1] is-level level-2

[SwitchD-isis-1] network-entity 20.0000.0000.0004.00

[SwitchD-isis-1] ipv6 enable

[SwitchD-isis-1] quit


[SwitchD-Vlan-interface300] isis ipv6 enable 1



[SwitchD-Vlan-interface301] isis ipv6 enable 1




Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 5 IPv6-BGP4+ Configuration


5-1

Chapter 5 IPv6-BGP4+ Configuration

Note:

This chapter describes only configuration for BGP4+. For BGP-related information,

refer to the part covering BGP configuration in the IPv4 Routing module.






5.1 BGP4+ Overview

The traditional BGP-4 manages only IPv4 routing information, thus other network layer

protocols such as IPv6 are limited when traveling across ASs.

To support multiple network layer protocols, IETF extended BGP-4 by introducing

BGP4+ that is defined in RFC 2858 (Multiprotocol Extensions for BGP-4).

To implement IPv6 support, BGP4+ reflects IPv6 network layer information into

attributes of Network Layer Reachable Information (NLRI) and NEXT_HOP.

NLRI attribute of BGP4+ involves:

MP_REACH_NLRI: Multiprotocol Reachable NLRI, for advertisement of next hop

information of reachable routes.

MP_UNREACH_NLRI: Multiprotocol Unreachable NLRI, for withdrawal of

unreachable routes.

NEXT_HOP attribute of BGP4+ is identified by IPv6 address, which is an IPv6 unicast

address or local link address.

BGP4+ utilizes BGP multiprotocol extensions for application in IPv6 networks. The

original message and routing mechanism of BGP is not changed.





5-2

5.2 Configuration Task List

Task Description

Configuring an IPv6 Peer Required

Advertising a Local IPv6 Route Optional

Configuring a Preferred Value for RoutesReceived from a Peer/Peer Group

Optional

Specifying a Local Update Source Interface to a Peer/Peer Group

Optional

Configuring a Non Direct EBGP Connection to a Peer/Peer Group

Optional

Configuring Description for a Peer/Peer

Group

Optional

Establishing No Session to a Peer/PeerGroup

Optional

Configuring BGP4+ Basic Functions

Logging Session State and Event Information of a Peer/Peer Group

Optional

Configuring BGP4+ Route Redistribution Optional

Advertising Default Route to a Peer/PeerGroup

Optional

Configuring Route Distribution Policy Optional

Configuring Route Reception Policy Optional

Configuring BGP4+ and IGP RouteSynchronization

Optional

Controlling Route Distribution and Reception

Configuring Route Dampening Optional

Configuring BGP4+ Preference and Default LOCAL_PREF and NEXT_HOPAttributes

Optional

Configuring the MED Attribute Optional

Configuring BGP4+ Route Attributes

Configuring the AS_PATH Attribute Optional

Configuring BGP4+ Timers Optional

Configuring BGP4+ Soft Reset OptionalAdjusting and Optimizing BGP4+ Networks Configuring the Maximum Number of

Load-Balancing Routes Optional

Configuring BGP4+ Peer Group Optional

Configuring BGP4+ Community OptionalConfiguring a LargeScale BGP4+ Network

Configuring a BGP4+ Router Reflector Optional





5-3

5.3 Configuring BGP4+ Basic Functions

5.3.1 Prerequisites

Before configuring this task, you have

Specified IP addresses for interfaces.

Enabled IPv6 function.

You need to decide on:

Local AS number and Router ID

Peer IPv6 address and AS number

Source interface of updates

5.3.2 Configuring an IPv6 Peer

To configure an IPv6 peer, use the following commands:



Enter BGP view bgp as-number Required


Specify a router ID router-id router-id

Optional

Required if no IPaddresses configured forLoopback interface andother interfaces

Enter IPv6 address familyview ipv6-family —

Specify an IPv6 peer andits AS number peer ipv6-address

as-number as-number Required


5.3.3 Advertising a Local IPv6 Route

To advertise a local route into the routing table, use the following commands:









5-4


Advertise a local routeinto BGP4+ routing table

network ipv6-address prefix-length [ short-cut |route-policy route-policy-name ]

Required

Not advertised by default

5.3.4 Configuring a Preferred Value for Routes Received from a Peer/Peer

Group

To configure a preferred value for routes received from a peer/peer group, use the

following commands:





Configure a preferredvalue for routes receivedfrom a peer/peer group

peer { ipv6-group-name | ipv6-address }preferred-value value

Optional

By default, the preferredvalue is 0.

5.3.5 Specifying a Local Update Source Interface to a Peer/Peer Group

To specify a local update source interface connected to a peer, use the following

commands:




Enter IPv6 address family

view

ipv6-family —

Specify a local updatesource interfaceconnected to a peer

peer { ipv6-group-name | ipv6-address }connect-interface interface-type interface-number

Required

By default, the sourceinterface of the optimalupdates is used.





5-5

Note:

To improve stability and reliability, you can specify the local interface of a BGP4+

connection as loopback interface. By doing so, a connection failure upon redundancy

available will not affect BGP4+ connection.

5.3.6 Configuring a Non Direct EBGP Connection to a Peer/Peer Group

To configure an EBGP connection to a peer not directly connected, use the following

commands:




Enter IPv6 address familyview

ipv6-family —

Configure a non directEBGP connection to apeer/peer group

peer { ipv6-group-name | ipv6-address }ebgp-max-hop [ hop-count ]

Required


Caution:

In general, direct links should be available between EBGP peers. If not available, you

can use the peer ebgp-max-hop command to establish a multi-hop TCP connection in

between. However, you need not use this command for direct EBGP connection using

loopback interfaces.

5.3.7 Configuring Description for a Peer/Peer Group

To configure description for a peer/peer group, use the following commands:




Enter IPv6 addressfamily view

ipv6-family —





5-6


Configure description fora peer/peer group

peer { ipv6-group-name | ipv6-address } description description-text

Optional


Note:

The peer group for which to configure description must have been created.

5.3.8 Establishing No Session to a Peer/Peer Group

To disable session establishment to a peer/peer group, use the following commands:





ipv6-family —

Disable sessionestablishment to apeer/peer group

peer { ipv6-group-name | ipv6-address } ignore

Optional

Not disabled by default

5.3.9 Logging Session State and Event Information of a Peer/Peer Group

To log on the session and event information of a peer/peer group, use the following

commands:




Enable global logging log-peer-changeOptional

Enabled by default


ipv6-family —

Enable to log session andevent information of apeer/peer group

peer { ipv6-group-name | ipv6-address }log-change

Optional

Enabled by default





5-7

Note:

Refer to BGP Commands in IPv4 Routing for information about the log-peer-change

command.

5.4 Controlling Route Distribution and Reception

The task includes routing information filtering, routing policy application and route

dampening.

5.4.1 Prerequisites

Before configuring this task, you have:

Enabled IPv6 function

Configured BGP4+ basic functions

You need to decide on:

ACL number

Routing policy names on both distribution and reception directions

Route dampening parameters: half-life, threshold values

5.4.2 Configuring BGP4+ Route Redistribution

To configure BGP4+ route redistribution and filtering, use the following commands:





Enable to redistributedefault route into the

BGP4+ routing table

default-route imported Optional


Enable to redistributeroutes from other routingprotocols

import-route protocol [ process-id ] [ medmed-value | route-policy route-policy-name ]*

Required






5-8

Note:

If the default-route imported command is not configured, using the import-route

command cannot redistribute any IGP default route.

5.4.3 Advertising Default Route to a Peer/Peer Group

To advertise default route to a peer/peer group, use the following commands:





Advertise a default routeto a peer/peer group

peer { ipv6-group-name | ipv6-address }default-route-advertise[ route-policy route-policy-name ]

Required

Not advertisedby default

Note:

With the peer default-route-advertise command used, the local router advertises a

default route with itself as the next hop to the specified peer/peer group, regardless of

whether the default route is available in the routing table.

5.4.4 Configuring Route Distribution Policy

To configure policies for route distribution, use the following commands:





Filter advertised routes

filter-policy { acl6-number | ipv6-prefix ipv6-prefix-name } export [ protocol process-id ]

Required

Not filtered by default





5-9


Apply a routing policy toroutes advertised to apeer/peer group

peer { ipv6-group-name |ipv6-address } route-policy route-policy-name export

Required

Not applied by default

Specify an IPv6 ACL tofiler routes advertised to apeer/peer group

peer { ipv6-group-name |ipv6-address } filter-policy acl6-number export

Required

Not specified bydefault

Specify an AS path ACLto filer routes advertisedto a peer/peer group

peer { ipv6-group-name |ipv6-address } as-path-acl as-path-acl-number export

Required


Specify an IPv6 prefix listto filer routes advertisedto a peer/peer group

peer { ipv6-group-name |ipv6-address } ipv6-prefix ipv6-prefix-name export

Required


Note:

Members of a peer group must have the same outbound route policy with the peer

group.

BGP4+ advertises routes not filtered by the specified policy to peers. Using the

protocol argument can filter only the specified protocol routes. If no protocol

specified, BGP4+ filters all routes to be advertised, including redistributed routes

and routes imported using the network command.

5.4.5 Configuring Route Reception Policy

To configure route reception policy, use the following commands:



Enter BGP view bgp as-number

Required

Not enabled bydefault


Filter received routesfilter-policy { acl6-number |ipv6-prefix ipv6-prefix-name } import

Required

Not filtered by default

Apply a routing policy toroutes imported from apeer/peer group

peer { ipv6-group-name |ipv6-address } route-policy route-policy-name import

Required






5-10


Specify an ACL to filterroutes imported from a

peer/peer group

peer { ipv6-group-name |ipv6-address } filter-policy

acl6-number import

Required

Not specified by

default

Specify an AS path ACLto filter routing informationimported from a peer/peergroup

peer { ipv6-group-name |ipv6-address } as-path-acl as-path-acl-number import

Required


Specify an IPv6 prefix listto filter routing informationimported from a peer/peergroup

peer { ipv6-group-name |ipv6-address } ipv6-prefix ipv6-prefix-name import

Required


Specify the upper limit ofaddress prefixes imported

from a peer/peer group

peer { ipv6-group-name | ipv6-address } route-limit

limit [ percentage ]

Optional

By default, no limit onprefixes

Note:

Only routes not filtered by the specified policy can be added into the local BGP4+

routing table.

Members of a peer group can have different inbound route policies.

5.4.6 Configuring BGP4+ and IGP Route Synchronization

With this feature enabled and when a non-BGP4+ router is responsible for forwarding

packets in an AS, BGP4+ speakers in the AS cannot advertise routing information to

outside ASs unless all routers in the AS know the latest routing information.

By default, when a BGP4+ router receives an IBGP route, it only checks the

reachability of the route’s next hop before advertisement. If the synchronization feature

is configured, only the IBGP route is advertised by IGP can the route be advertised to

EBGP peers.

To configure BGP4+ and IGP route synchronization, use the following commands:





Enable routesynchronization between

BGP4+ and IGP

synchronizationRequired






5-11

5.4.7 Configuring Route Dampening

To configure BGP route dampening, use the following commands:





Configure BGP4+ routedampening parameters

dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ]*

Optional


5.5 Configuring BGP4+ Route Attributes

This section describes how to use BGP4+ route attributes to modify BGP4+ routing

policy. These attributes are:

BGP4+ protocol preference

Default LOCAL_PREF attribute

MED attribute

NEXT_HOP attribute

AS_PATH attribute

5.5.1 Prerequisites

Before configuring this task, you have:



5.5.2 Configuring BGP4+ Preference and Default LOCAL_PREF and

NEXT_HOP Attributes

To do so, use the following commands:





ipv6-family —





5-12


Configure preferencevalues for BGP4+external, internal, localroutes

preference { external-preference internal-preference local-preference |route-policy route-policy-name }

Optional

The default preference

values of external, internaland local routes are 255,255, 130 respectively

Configure the defaultvalue for local preference

defaultlocal-preference value

Optional

The value defaults to 100

Advertise routes to apeer/peer group with thelocal router as the nexthop

peer { ipv6-group-name | ipv6-address }next-hop-local

Optional

By default, the feature isavailable for routesadvertised to the EBGPpeer/peer group, but not

available to the IBGPpeer/peer group

Note:

To make sure an IBGP peer can find the correct next hop, you can configure routes

advertised to the peer to use the local router as the next hop. If BGP load balancing

is configured, the local router sets the next hop of outbound routes for a peer/peer

group to itself regardless of whether the peer next-hop-local command is

configured.

In a special networking environment of third-party next hop (that is, a broadcast

network with two BGP4+ peers connected to the same network segment), by default,

the router does not use its own address as the next hop when advertising routes to

EBGP peers/peer groups; the router uses its own address as the next hop only after

the peer next-hop-local command is used.

5.5.3 Configuring the MED Attribute

To configure the MED attribute, use the following commands:





ipv6-family —

Configure a default MEDvalue

default med med-value Optional

Defaults to 0





5-13


Enable to compare MEDvalues of routes fromdifferent EBGP peers

compare-different-as-med

Optional


Prioritize MED values ofroutes from each AS

bestroute compare-medOptional


Prioritize MED values ofroutes from confederationpeers

bestroutemed-confederation

Optional


5.5.4 Configuring the AS_PATH Attribute






ipv6-family —

Allow local AS number inAS_PATH of routes froma peer/peer group

peer { ipv6-group-name |ipv6-address }allow-as-loop [ number ]

Optional

Not allowed by default

Specify a fake AS numberfor a peer/peer group

peer { ipv6-group-name |ipv6-address } fake-as as-number

Optional

Not specified by default

Neglect the AS_PATHattribute for best routeselection

bestrouteas-path-neglect

Optional

Not neglected by default

Configure to carry onlythe public AS number inupdates sent to apeer/peer group

peer { ipv6-group-name |ipv6-address }public-as-only

Optional

By default, BGP updatescarry private AS number

Substitute local ASnumber for the ASnumber of a peer/peergroup indicated in theAS_PATH attribute

peer { ipv6-group-name |ipv6-address }substitute-as

Optional

Not substituted by default

5.6 Adjusting and Optimizing BGP4+ Networks

This section describes configurations of BGP4+ timers, BGP4+ connection soft reset

and the maximum number of load balancing routes.





5-14

1) BGP4+ timers

After establishing a BGP4+ connection, two routers send keepalive messages

periodically to each other to keep the connection. If a router receives no keepalive

message from the peer after the holdtime elapses, it tears down the connection.

When establishing a BGP4+ connection, the two parties compare their holdtime values,

taking the shorter one as the common holdtime. If the holdtime is 0, neither keepalive

massage is sent, nor holdtime is checked.

2) BGP4+ connection soft reset

After modifying a route selection policy, you have to reset BGP4+ connections to make

the new one take effect, causing a short time disconnection. The current BGP4+

implementation supports the route-refresh feature that enables dynamic BGP4+

routing table refresh without needing to disconnect BGP4+ links.

With this feature enabled on all BGP4+ routers in a network, when a routing policy

modified on a router, the router advertises a route-refresh message to its peers, which

then send their routing information back to the router. Therefore, the local router can

perform dynamic routing information update and apply the new policy without tearing

down connections.

If a router not supporting route-refresh exists in the network, you need to configure the

peer keep-all-routes command on the router to save all route updates, and then use

the refresh bgp ipv6 command to soft-reset BGP4+ connections.

5.6.1 Prerequisites

Before configuring BGP4+ timers, you have:



5.6.2 Configuring BGP4+ Timers






ipv6-family —





5-15


Specifykeepaliveinterval andholdtime

timer keepalive keepalive hold holdtime

ConfigureBGP4+timers

Configurekeepaliveinterval andholdtime for apeer/peergroup

peer { ipv6-group-name | ipv6-address } timer keepalive keepalive holdholdtime

Optional

The keepalive intervaldefaults to 60 seconds,holdtime defaults to180 seconds.

Configure the interval forsending the same update to

a peer/peer group

peer { ipv6-group-name | ipv6-address }route-update-interval

seconds

Optional

The interval for sendingthe same update to anIBGP peer or an EBGPpeer defaults to 15seconds or 30 seconds

Note:

Timers configured using the timer command have lower priority than timers

configured using the peer timer command.

The holdtime interval must be at least three times the keepalive interval.

5.6.3 Configuring BGP4+ Soft Reset

I. Enable route refresh

To enable route refresh, use the following commands:




Enter IPv6 addressfamily view

ipv6-family —

Enable route refreshpeer { ipv6-group-name |ipv6-address } capability-advertise route-refresh

Optional

Enabled bydefault





5-16

II. Perform manual soft-reset

To perform manual soft reset, use the following commands:





ipv6-family —

Save all routes from apeer/peer group, notletting them go throughthe inbound policy

peer { ipv6-group-name | ipv6-address }keep-all-routes

Optional

Not saved by default.

Return to user view return —

Soft-reset BGP4+connections manually

refresh bgp ipv6 { all |ipv6-address | group ipv6-group-name | external |internal } { export | import }

Required

Note:

If the peer keep-all-routes command is used, all routes from the peer/peer group will

be saved regardless of whether filtering policy available. These routes will be used to

generate BGP4+ routes after soft-reset is performed.

5.6.4 Configuring the Maximum Number of Load-Balancing Routes

To configure the maximum number of load balancing routes, use the following

commands:





ipv6-family —

Configure the maximumnumber of load balancingroutes

balance number

Required

By default, no loadbalancing is enabled.





5-17

5.7 Configuring a Large Scale BGP4+ Network

For easy management and streamlined configurations, an administrator can allocate

the BGP4+ peers having the same update policy to the same logical organization. Such

organizations are known as peer groups. A policy configured for a peer group applies to

all the members in the group.

Each time the configuration of the peer group changes, the configuration of each group

member changes accordingly. You may, however, configure certain attributes for a

certain member by specifying its IPv6 address so that the member is not subject to the

peer group’s configuration in terms of these attributes.

Normally, the peers in the same AS are configured as a peer group. You can also add

the peers of other ASs to the group. All the IBGP peers can be configured as another

peer group. Peer groups are created according to service logic.

A peer group allows a group of peers to share the same policy, while a community

allows a group of BGP4+ routers in multiple ASs to share the same policy. Community

is a route attribute propagated among BGP4+ peers and not restricted by ASs.

To guarantee connectivity between IBGP peers, you need to make them fully meshed,

but it becomes unpractical when there are too many IBGP peers. Using router reflector

or confederation can solve it. In a large-scale AS, both of them can be used.

Confederation configuration of BGP4+ is identical to that of BGP, so it is not mentioned

here. The following describes:

Configuring BGP4+ peer group

Configuring BGP4+ community

Configuring BGP4+ router reflector

5.7.1 Prerequisites

Before configuring BGP4+ peer group, you have:

Made peer nodes accessible at network layer

Enabled BGP and configured router ID.

5.7.2 Configuring BGP4+ Peer Group

I. Create an IBGP peer group

To create an IBGP group, use the following commands:









5-18



Create an IBGP peergroup

group ipv6-group-name [ internal ]

Required

Add a peer into the grouppeer ipv6-address group ipv6-group-name [ as-number as-number ]

Required

Not added by default

II. Create a pure EBGP peer group

To configure a pure EBGP group, use the following commands:






ipv6-family —

Create an EBGP peergroup

group ipv6-group-name external

Required

Configure the AS number

for the peer group

peer ipv6-group-name

as-number as-number

Required


Add an IPv6 peer into thepeer group

peer ipv6-address group ipv6-group-name

Required


Note:

To create a pure EBGP peer group, you need to specify the AS number for the peer

group.

If a peer was added into an EBGP peer group, you cannot specify any AS number

for the peer group.





5-19

III. Create a mixed EBGP peer group







ipv6-family —

Create an EBGP peergroup

group ipv6-group-name external

Required

Specify the AS number of

an IPv6 peer

peer ipv6-address

as-number as-number

Required

Not specified by default

Add the IPv6 peer into thepeer group

peer ipv6-address group ipv6-group-name

Required


Note:

When creating a mixed EBGP peer group, you need to create a peer and specify its AS

number that can be different from AS numbers of other peers, but you cannot specify

any AS number for the EBGP peer group.

5.7.3 Configuring BGP4+ Community

I. Advertise community attribute to a peer/peer group







ipv6-family —

Advertise communityattribute to a peer/peergroup

peer { ipv6-group-name | ipv6-address }advertise-community

Required

Not advertised by default





5-20

II. Apply a routing policy to routes advertised to a peer/peer group






ipv6-family —

Apply a routing policy toroutes advertised to apeer/peer group

peer { ipv6-group-name |ipv6-address }route-policy route-policy-name export

Required


Note:

When configuring BGP4+ community, you need to configure a routing policy to

define the community attribute, and apply the routing policy to route advertisement.

For routing policy configuration, refer to Chapter 6 Routing Policy Configuration .

5.7.4 Configuring a BGP4+ Router Reflector

To configure a BGP4+ router reflector, use the following commands:





ipv6-family —

Configure the router as arouter reflector and

specify a peer/peer groupas a client

peer { ipv6-group-name | ipv6-address }

reflect-client

Required


Enable route reflectionbetween clients

reflect between-clients Optional

Enabled by default

Configure the cluster IDof the router reflector

reflector cluster-id cluster-id

Optional

By default, a routerreflector uses its router IDas the cluster ID





5-21

Note:

In general, it is not required to make clients of a router reflector fully meshed. The

router reflector forwards routing information between clients. If clients are fully

meshed, you can disable route reflection between clients to reduce metrics.

If a cluster has multiple router reflectors, you need to specify the same cluster ID for

these router reflectors to avoid routing loops.

5.8 Displaying and Maintaining BGP4+ Configuration

5.8.1 Displaying BGP


Display peer groupinformation

display bgp ipv6 group[ ipv6-group-name ]

Display BGP4+advertised routinginformation

display bgp ipv6 network

Display AS pathinformation

display bgp ipv6 paths[ as-regular-expression ]

Display BGP peer

information

display bgp ipv6 peer [ ipv6-address { log-info | verbose } | ipv6-group-name log-info | verbose ]

Display BGP4+ routingtable information

display bgp ipv6 routing-table[ ipv6-address prefix-length ]

Display routinginformation matchedby a AS path ACL

display bgp ipv6 routing-tableas-path-acl as-path-acl-number

Display BGP4+community routinginformation

display bgp ipv6 routing-tablecommunity [ aa:nn <1-13> ][ no-advertise | no-export | no-export-subconfed ]*

[ whole-match ]

Display routinginformation matchedby a BGP4+community list

display bgp ipv6 routing-table community-list { basic-community-list-number [ whole-match ] |adv-community-list-number }&<1-16>

Display BGP4+dampened routinginformation

display bgp ipv6 routing-tabledampened

Display BGP4+dampening parameter

information

display bgp ipv6 routing-table

dampening parameter

Available inany view





5-22


Display routinginformation originatedfrom different ASs

display bgp ipv6 routing-tabledifferent-origin-as

Display routing flapstatistics

display bgp ipv6 routing-tableflap-info [ regular-expression as-regular-expression | as-path-aclas-path-acl-number | network-address [ prefix-length [ longer-match ] ] ]

Display routinginformation sentto/received from a peer

display bgp ipv6 routing-table peeripv6-address { advertised-routes | received-routes } [ network-address prefix-length | statistic ]

Display routing

information matchedby a regularexpression

display bgp ipv6 routing-table

regular-expression as-regular-expression

Display BGP4+ routingstatistics

display bgp ipv6 routing-table statistic

5.8.2 Resetting BGP4+ Connections


Reset all BGP4+ connections reset bgp ipv6 all

Reset the BGP4+ connectionto an AS

reset bgp ipv6 as-number

Reset the BGP4+ connectionto a peer

reset bgp ipv6 ipv6-address [ flap-info ]

Reset all EBGP connections reset bgp ipv6 external

Reset the BGP4+ connectionto a peer group

reset bgp ipv6 group ipv6-group-name

Reset all IBGP connections reset bgp ipv6 internal

Available in userview

5.8.3 Clearing BGP4+ Information


Clear dampeningrouting informationand releasesuppressed routes

reset bgp ipv6 dampening[ ipv6-address prefix-length ]






5-23


Clear route flapinformation

reset bgp ipv6 flap-info [ ipv6-address/prefix-length | regexpas-path-regexp | as-path-aclas-path-acl-number ]

5.9 BGP4+ Configuration Examples

Note:

Some BGP4+ configuration examples are similar to those of BGP4, so refer to BGP

Configuration in IPv4 Routing for related information.

5.9.1 BGP4+ Basic Configuration


In Figure 5-1 are all BGP4+ switches. Between Switch A and Switch B is an EBGP

connection. Switch B, Switch C and Switch D are IBGP fully meshed.

II. Network diagram

SwitchC

SwitchD

Vlan-interface100

9:1::1/64



AS 65009


SwitchB

SwitchA



AS 65008

Vlan-interface2009:2::2/64Vlan-interface300

9:3::1/64


Figure 5-1 BGP4+ basic configuration network diagram



2) Configure IBGP connections







5-24

[SwitchB] ipv6

[SwitchB] bgp 65009

[SwitchB-bgp] router-id 2.2.2.2

[SwitchB-bgp] ipv6-family

[SwitchB-bgp-af-ipv6] peer 9:1::2 as-number 65009

[SwitchB-bgp-af-ipv6] peer 9:3::2 as-number 65009

[SwitchB-bgp-af-ipv6] quit

[SwitchB-bgp] quit



[SwitchC] ipv6

[SwitchC] bgp 65009

[SwitchC-bgp] router-id 3.3.3.3

[SwitchC-bgp] ipv6-family

[SwitchC-bgp-af-ipv6] peer 9:3::1 as-number 65009

[SwitchC-bgp-af-ipv6] peer 9:2::2 as-number 65009

[SwitchC-bgp-af-ipv6] quit

[SwitchC-bgp] quit



[SwitchD] ipv6

[SwitchD] bgp 65009

[SwitchD-bgp] router-id 4.4.4.4

[SwitchD-bgp] ipv6-family

[SwitchD-bgp-af-ipv6] peer 9:1::1 as-number 65009

[SwitchD-bgp-af-ipv6] peer 9:2::1 as-number 65009

[SwitchD-bgp-af-ipv6] quit

[SwitchD-bgp] quit

3) Configure the EBGP connection



[SwitchA] ipv6

[SwitchA] bgp 65008

[SwitchA-bgp] router-id 1.1.1.1

[SwitchA-bgp] ipv6-family

[SwitchA-bgp-af-ipv6] peer 10::1 as-number 65009

[SwitchA-bgp-af-ipv6] quit

[SwitchA-bgp] quit


[SwitchB] bgp 65009





5-25


[SwitchB-bgp-af-ipv6] peer 10::2 as-number 65008

# Display IPv6 peer information on Switch B.

[SwitchB] display bgp ipv6 peer

BGP local router ID : 2.2.2.2

Local AS number : 65009

Total number of peers : 3 Peers in established state : 3

Peer V AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

10::2 4 65008 3 3 0 0 00:01:16 Established

9:3::2 4 65009 2 3 0 0 00:00:40 Established

9:1::2 4 65009 2 4 0 0 00:00:19 Established

# Display IPv6 peer information on Switch C.

[SwitchC] display bgp ipv6 peer

BGP local router ID : 3.3.3.3

Local AS number : 65009

Total number of peers : 2 Peers in established state : 2

Peer V AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

9:3::1 4 65009 4 4 0 0 00:02:18 Established

9:2::2 4 65009 4 5 0 0 00:01:52 Established

Switch A and B established an EBGP connection; Switch B, C and D established IBGP

connections with each other.

5.9.2 BGP4+ Router Reflector Configuration


Switch B receives an EBGP update and sends it to Switch C, which is configured as a

router reflector with two clients: Switch B and Switch D.

Switch B and Switch D need not establish an IBGP connection because Switch C

reflects updates between them.





5-26

II. Network diagram

RouteReflector

IBGPIBGP

AS200

SwitchC








SwitchA

AS100 SwitchB SwitchD

Figure 5-2 BGP4+ router reflector configuration network diagram


1) Configure IPv6 addresses for VLAN interfaces (omitted)

2) Configure BGP4+ basic functions



[SwitchA] ipv6

[SwitchA] bgp 100

[SwitchA-bgp] router-id 1.1.1.1

[SwitchA-bgp] ipv6-family

[SwitchA-bgp-af-ipv6] peer 100::2 as-number 200

[SwitchA-bgp-af-ipv6] network 1:: 64

[SwitchA-bgp-af-ipv6] quit

#Configure Switch B.


[SwitchB] ipv6

[SwitchB] bgp 200

[SwitchB-bgp] router-id 2.2.2.2






[SwitchC] ipv6

[SwitchC] bgp 200

[SwitchC-bgp] router-id 3.3.3.3

[SwitchC-bgp] ipv6-family

[SwitchC-bgp-af-ipv6] peer 101::2 as-number 200

[SwitchC-bgp-af-ipv6] peer 102::2 as-number 200





5-27



[SwitchD] ipv6

[SwitchD] bgp 200

[SwitchD-bgp] router-id 4.4.4.4

[SwitchD-bgp] ipv6-family

[SwitchD-bgp-af-ipv6] peer 102::1 as-number 200

3) Configure router reflector

# Configure Switch C as a router reflector, Switch B and Switch D as its clients.

[SwitchC-bgp-af-ipv6] peer 101::2 reflect-client

[SwitchC-bgp-af-ipv6] peer 102::2 reflect-client

Use the display bgp ipv6 routing-table command on Switch B and Switch D

respectively, you can find both of them have learned the network 1::/64.

5.10 Troubleshooting BGP4+ Configuration

5.10.1 No BGP4+ Peer Relationship Established

I. Symptom

Display BGP4+ peer information using the display bgp ipv6 peer command. The state

of the connection to the peer cannot become established.

II. Analysis

To become BGP4+ peers, any two routers need to establish a TCP session using port

179 and exchange open messages successfully.

III. Processing steps

1) Use the display current-configuration command to verify the peer’s AS number.

2) Use the display bgp ipv6 peer command to verify the peer’s IPv6 address.

3) If the loopback interface is used, check whether the peer connect-interface

command is configured.

4) If the peer is not directly connected, check whether the peer ebgp-max-hop

command is configured.

5) Check whether a route to the peer is available in the routing table.

6) Use the ping command to check connectivity.

7) Use the display tcp status command to check the TCP connection.

8) Check whether an ACL for disabling TCP port 179 is configured.



Operation Manual - IPv6 RoutingQuidway S3500-EA Series Ethernet Switches Chapter 6 Routing Policy Configuration


6-1

Chapter 6 Routing Policy Configuration

Note:


configuring IPv6 routing policy.

All the IPv6 routing policy related configuration mentioned in this manual assumes

that the system already operates in IPv4/IPv6 dual-stack mode. For dual stack

mode configuration, see the part covering dual stack in the IPv6 Configuration

module.

A routing policy is used on the router for route inspection, filtering, attributes modifying

when routes are received, advertised, or redistributed.

6.1 Introduction to Routing Policy

6.1.1 Routing Policy and Policy Routing

By modifying route attributes (including reachability), routing policy is adopted to

change routing path for network traffic.

When distributing or receiving routing information, a router can apply some policy to

filter routing information, for example, a router handles only routing information that

matches some rules, or a routing protocol redistributes from other protocols only routes

matching some rules and modifies some attributes of these routes to satisfy its needs.

To implement routing policy, first define the features of routing information, namely, a

set of matching rules. You can make definitions according to attributes in routing

information, such as destination address, advertising router’s address. The matching

rules can be set beforehand and then apply them to a routing policy for route

distribution, reception and redistribution.

6.1.2 Filters

Routing protocols can use five filters: ACL, IP prefix list, AS path, community-list and

route policy.

I. ACL

When defining an ACL, you can specify IP addresses and prefixes for matching

destinations or next hops of routing information.





6-2

For ACL configuration, refer to ACL Operation manual .

II. IP prefix list

IP-prefix list plays a role similar to ACL, but it is more flexible than ACL and easier tounderstand. When IP-prefix list is applied for routing information filtering, its matching

object is the destination address information field of routing information.

An IP-prefix list is identified by the IP-prefix list name. Each IP-prefix list can comprise

multiple items, and each item, which is identified by an index number, can specify a

matching range in network prefix format. The index number indicates the matching

sequence in the IP-prefix list.

During matching, a router checks list items identified by index number in the ascending

order. If one item matched, the IP-prefix list filtering is passed, without needing to match

the next item.

III. AS-path ACL

AS-path ACL only applies to BGP4+. There is an AS-path field in the BGP4+ routing

information packets. As-path-acl specifies matching conditions according to the

AS-path field.

IV. Community list

The community list only applies to BGP4+. The BGP4+ routing information packet

contains a community attribute field to identify a community. Based on the community

attribute, the community-list specifies matching conditions.

V. Routing policy

A routing policy is used for matching some attributes in given routing information and

modifying the attributes of the information if matching conditions are satisfied. A routing

policy can utilize the above filters to define its own matching rules.

A routing policy can comprise multiple nodes, which are in logic OR relationship. Each

node is a matching unit, and the system checks nodes in the order of node sequence

number. Once the matching test of a node is passed, the route-policy is passed without

needing to match other nodes.

Each node comprises a set of if-match and apply clauses. The if-match clauses

define the matching rules. The matching objects are some attributes of routing

information. The different if-match clauses on the same node is in logic AND

relationship. Only when the matching conditions specified by all the if-match clauses

on a node are satisfied, can routing information passes the matching test of the node.

The apply clauses specify the actions performed after the node matching test passed,

concerning the attribute settings for the routing information.





6-3

6.1.3 Routing Policy Application

Routing policy applies in two ways:

When redistributing routes from other routing protocols, a routing protocolredistributes only routes matching rules defined in a routing policy.

When receiving or advertising routing information, a routing protocol uses a

routing policy to filter routing information.

6.2 Defining Filtering Lists

6.2.1 Prerequisites

Before configuring this task, prepare the following data:

IP-prefix list name Matching address range

6.2.2 Defining an IPv6-prefix List

Identified by name, each IPv6 prefix list can comprise multiple items. Each item

specifies a matching address range in the form of network prefix, which is identified by

index number.

During matching, the system checks list items identified by index number in the

ascending order. If one item is matched, IP-prefix list filtering is passed, without

needing to match other items.

To define an IPv6 prefix list, use the following commands:



Define an IPv6prefix list

ip ipv6-prefix ipv6-prefix-name [ indexindex-number ] { deny | permit } ipv6-address prefix-length [ greater-equal min-prefix-length ][ less-equal max-prefix-length ]

Required

Not defined bydefault

Note:

If all items are set to the deny mode, no route can pass the IPv6 prefix list. It is

recommended to define the permit :: 0 less-equal 128 item following multiple deny

mode items to allow other IPv6 routing information to pass.

For example, the following configuration filters routes 2000:1::/48, 2000:2::/48 and

2000:3::/48, but allows other routes to pass.





6-4

<Sysname> system-view

[Sysname] ip ipv6-prefix abc index 10 deny 2000:1:: 48



[Sysname] ip ipv6-prefix abc index 40 permit :: 0 less-equal 128

6.2.3 Defining an AS Path ACL

You can define multiple items for an AS path ACL that is identified by its number. During

matching, the relation between items is logic OR, that is, if routing information matches

one of these items, it passes the AS path ACL.

To define an AS path ACL, use the following commands:



Define an AS pathACL

ip as-path-aclas-path-acl-number { deny |permit } regular-expression

Required

Not defined by default

6.2.4 Defining a Community List

You can define multiple items for a community list that is identified by its number. During

matching, the relation between items is logic OR, that is, if routing information matchesone of these items, it passes the community list.

To define a community list, use the following commands:



Define abasiccommunitylist

ip community-list basic-comm-list-num { deny |permit } [ community-number-list ][ internet | no-advertise | no-export| no-export-subconfed ]*

Define a

communitylist Define anadvancedcommunitylist

ip community-list adv-comm-filter-num { deny |permit } regular-expression

Required todefine either

Not defined bydefault

6.3 Configuring a Routing Policy

A routing policy is used to filter routing information according to some attributes, and

modify some attributes of the routing information that matches the routing policy.

Matching rules can be configured using filters above mentioned.





6-5

A routing policy can comprise multiple nodes, each node contains:

if-match clauses: define the matching rules routing information must satisfy. The

matching objects are some attributes of routing information.

apply clauses: specifies the actions performed after specified matching rulessatisfied, concerning attribute settings for passed routing information.

6.3.1 Prerequisites

Before configuring this task, you have completed:

Filtering list configuration

Routing protocol configuration

You also need to decide on:

Name of routing policy, node sequence numbers Matching rules

Attributes to be modified

6.3.2 Creating a Routing Policy

To create a routing policy, use the following commands:



Create a routingpolicy and enter itsview

route-policy route-policy-name { permit |deny } node node-number

RequiredNot created by default

Note:

If a node is specified as permit, routing information meeting the node’s conditions

will be handled using the apply clauses of this node, without needing to match the

next node. If routing information does not meet the node’s conditions, it will go to the

next node for matching.

If a node is specified as deny, the apply clauses of the node will not be executed.When routing information meets all if-match clauses, it cannot pass the node, nor

can it go to the next node. If route information cannot meet any if-match clause of

the node, it will go to the next node for matching.

When a routing policy is defined with more than one node, at least one node should

be configured using the permit keyword. If the routing policy is used to filter routing

information, routing information that does not meet any node’s conditions cannot

pass the routing policy. If all nodes of the routing policy are set using the deny

keyword, no routing information can pass it.





6-6

6.3.3 Defining if-match Clauses for the Routing Policy

To define if-match clauses for a route-policy, use the following command:



Enter routing policy view route-policy route-policy-name { permit |deny } node node-number

Required

Set conditions to matchIPv6 routing information

if-match ipv6 { address |next-hop | route-source }{ acl acl-number | prefix-list ipv6-prefix-name }

Optional


Set conditions to match

AS path field of BGP4+routing information

if-match as-path as-path-acl-number &<1-16>

Optional


Match communityattribute of BGP4+ routinginformation

if-match community { basic-community-list-number [ whole-match ] |adv-community-list-number }&<1-16>

Optional


Match route cost ofrouting information

if-match cost value

Optional


Match outbound interfaceof routing information

if-match interface{ interface-type interface-number }&<1-16>

OptionalNot configured bydefault

Match types of routes

if-match route-type { internal | external-type1 |external-type2 |external-type1or2 |is-is-level-1 | is-is-level-2 |nssa-external-type1 |nssa-external-type2 |nssa-external-type1or2 }*

Optional


Configure the matchingcondition for the tag fieldof the routing information

if-match tag value OptionalNot configured bydefault





6-7

Note:

The if-match clauses of a route-policy are in logic AND relationship, namely, routing

information has to satisfy all if-match clauses before executed with apply clauses.

You can specify no or multiple if-match clauses for a routing policy. If no if-match

clause is specified, and the routing policy is in permit mode, all routing information

can pass the node, or in deny mode, no routing information can pass.

6.3.4 Defining apply Clauses for the Routing Policy

To define apply clauses for a route-policy, use the following command:

To do… Use the command… RemarksEnter system view system-view —

Create a routingpolicy and enter itsview

route-policy route-policy-name { permit | deny } node node-number

Required

Not created by default

Set AS_PATH ofBGP4+ routinginformation

apply as-pathas-number &<1-10> [ replace ]

Optional

Not set by default

Specify acommunity list

according to whichto delete communityattributes of BGP4+routing information

apply comm-list comm-list-number delete

Optional


Set communityattribute of BGP4+routing information

apply community { none |additive | { community-number &<1-16> |aa:nn &<1-16> |no-export-subconfed | no-export | no-advertise }*[ additive ] }

Optional

Not set by default

Set the cost ofrouting information apply cost [ + | - ] value

Optional

Not set by default

Set the cost type ofrouting information

apply cost-type { external |internal | type-1 | type-2 }

Optional

Not set by default

Set the next hop

for IPv6 routinginformation

apply ipv6 next-hop ipv6-address

Optional

Not set by default

Redistribute routesto a specified ISISlevel

apply isis { level-1 | level-1-2 |level-2 }

Optional






6-8


Set the localpreference ofBGP4+ routinginformation

apply local-preference preference

Optional

Not set by default

Set origin attributesof BGP4+ routinginformation

apply origin { igp | egp as-number | incomplete }

Optional

Not set by default

Set routing protocolpreference

apply preference preference Optional

Not set by default

Set the preferredvalue of BGProuting information

apply preferred-value preferred-value

Optional

Not set by default

Set the tag field ofrouting information

apply tag value OptionalNot set by default

Note:

The apply ipv6 next-hop commands do not apply to redistributed IPv6 routes.

6.4 Displaying and Maintaining the Routing Policy


Display BGP4+ AS pathACL information

display ip as-path-acl [ as-path-acl-number ]

Display BGP4+community list information

display ip community-list [ basic-community-list-number | adv-community-list-number ]

Display IPv6 prefix liststatistics

display ip ipv6-prefix [ ipv6-prefix-name ]

Display routing policyinformation

display route-policy [ route-policy-name ]


Clear IPv6 prefix statisticsreset ip ipv6-prefix[ ipv6-prefix-name ]






6-9

6.5 Routing Policy Configuration Example

6.5.1 Applying Routing Policy When Redistributing IPv6 Routes


Enable RIPng and configure three static routes on Switch A.

Apply a routing policy when redistributing static routes, making routes in 20::0/32

and 40::0/32 pass, routes in 30::0/32 filtered.

Display RIPng routing table information on Switch B to verify the configuration.

II. Network diagram

20::/3230::/32

SwitchA


SwitchB

40::/32 Vlan-interface10010::1/32

Vlan-interface200

11::1/32

Figure 6-1 Network diagram for routing policy application to route redistribution


1) Configure Switch A.

# Configure IPv6 addresses for Vlan-interface 100 and Vlan-interface 200.


[SwitchA] ipv6


[SwitchA-Vlan-interface100] ipv6 address 10::1 32



[SwitchA-Vlan-interface200] ipv6 address 11::1 32


# Enable RIPng on Vlan-interface 100.




# Configure three static routes.

[SwitchA] ipv6 route-static 20:: 32 11::2



# Configure routing policy.

[SwitchA] ip ipv6-prefix a index 10 permit 30:: 32

[SwitchA] route-policy static2ripng deny node 0





6-10

[SwitchA-route-policy] if-match ipv6 address prefix-list a

[SwitchA-route-policy] quit

[SwitchA] route-policy static2ripng permit node 10

[SwitchA-route-policy] quit

# Enable RIPng and redistribute static routes.

[SwitchA] ripng

[SwitchA-ripng-1] import-route static route-policy static2ripng

2) Configure Switch B.

# Configure the IPv6 address for Vlan-interface 100.

[SwitchB] ipv6


[SwitchB-Vlan-interface100] ipv6 address 10::2 32

# Enable RIPng on Vlan-interface 100.



# Enable RIPng.

[SwitchB] ripng

# Display RIPng routing table information.

[SwitchB-ripng-1] display ripng 1 route


----------------------------------------------------------------

Peer FE80::7D58:0:CA03:1 on Vlan-interface 100

Dest 10::/32,

via FE80::7D58:0:CA03:1, cost 1, tag 0, A, 18 Sec

Dest 20::/32,


Dest 40::/32,


6.6 Troubleshooting Routing Policy Configuration

6.6.1 IPv6 Routing Information Filtering Failed

I. Symptom

Filtering routing information failed, while routing protocol runs normally.

II. Analysis

At least one item of the IPv6 prefix list should be configured as permit mode, and at

least one node of the Route-policy should be configured as permit mode.




III. Processing procedure

1) Use the display ip ipv6-prefix command to display IP prefix list.

2) Use the display route-policy command to display route policy information.

Best_IPv6 Routing Operation

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Transcript of Best_IPv6 Routing Operation