© 2000, Cisco Systems, Inc. 9-1 Optimizing Routing Update Operation Chapter 9.

© 2000, Cisco Systems, Inc. 9-1

Optimizing Routing Update Operation

Optimizing Routing Update Operation

Chapter 9Chapter 9

© 2000, Cisco Systems, Inc. www.cisco.com BSCN v1.0—9-2

Objectives

Upon completion of this chapter, you will be able to perform the following tasks:• Select and configure the different ways to control

route update traffic

• Configure route redistribution in a network that does not have redundant paths between dissimilar routing processes

• Configure route redistribution in a network that has redundant paths between dissimilar routing processes


Objectives (cont.)Objectives (cont.)

• Resolve path selection problems that result in a redistributed network

• Verify route redistribution

• Configure policy-based routing using route maps

• Given a set of network requirements, configure redistribution between different routing domains and verify proper operation (within described guidelines) of your routers

• Given a set of network requirements, configure policy-based routing within your pod and verify proper operation (within described guidelines) of your routers

© 2000, Cisco Systems, Inc. www.cisco.com 9-4

Redistribution Between Multiple Routing Protocols

Redistribution Between Multiple Routing Protocols


• Interim during conversion

• Application-specific protocols

–One size does not always fit all

• Political boundaries

–Groups that do not work and play nicely with others

• Mismatch between devices

–Multivendor interoperability

–Host-based routers

When Do You Use Multiple Routing Protocols?


AS 200IGRP172.16.0.0

S0S1AS 300EIGRP192.168.5.0

What Is Redistribution?

A


• Routes are learned from another routing protocol when a router redistributes the information between the protocols

IP Routing TableI 192.168.5.0I 172.16.1.0I 172.16.2.0I 172.16.3.0

IP Routing Table

D EX 172.16.0.0D 192.168.5.8D 192.168.5.16D 192.168.5.24

S1 Advertises Routes from EIGRP to IGRP

S0 Advertises Routes from IGRP to EIGRP

AS 200IGRP172.16.0.0

S0S1AS 300EIGRP192.168.5.0

What Is Redistribution?

ABC

Boundary Router


Redistribution Implementation Considerations

172.16

RIP

172.16

EIGRP

RIP

172.16.0.0

AS 300EIGRP

172.16

RIP

172.16

EIGRP

• Routing feedback– Suboptimal path selection– Routing loops

• Incompatible routing information• Inconsistent convergence time


• Different protocols use different metrics

• Metrics are difficult to compare algorithmically

• Therefore, need a selection process:

1—Which protocol do you believe the most? Use the administrative distance

2—Then decide which metric is the best

Selecting the Best Route


Which Protocol to Believe?

Connected interface 0Static route out an interface 0Static route to a next hop 1EIGRP summary route 5External BGP 20Internal EIGRP 90IGRP 100OSPF 110IS-IS 115RIP v1, v2 120EGP 140External EIGRP 170Internal BGP 200Unknown 255

Route Source Default Distance


Seed Metric

• The first or seed metric for a route is derived from being directly connected to a router interface

• But redistributed routes are not physically connected

–Use the default-metric command to establish the seed metric for the route

–Once a compatible metric is established, the metric will increment just like any other

route

–Set default metric larger than the largest native metric


Redistribution Supports All Protocols

RtrA(config-router)#redistribute ? bgp Border Gateway Protocol (BGP) connected Connected egp Exterior Gateway Protocol (EGP) eigrp Enhanced Interior Gateway Routing Protocol (EIGRP) igrp Interior Gateway Routing Protocol (IGRP) isis ISO IS-IS iso-igrp IGRP for OSI networks mobile Mobile routes odr On Demand stub Routes ospf Open Shortest Path First (OSPF) rip Routing Information Protocol (RIP) static Static routes


• IPX RIP redistribution with EIGRP is enabled by default

• AppleTalk RTMP redistribution is enabled by default

• Redistribution of IGRP in the same autonomous system is automatic; manual if different autonomous system

• Other protocols require manual redistribution

IPX

EIGRP

IPX

AppleTalk

IP

AppleTalk

IP

Redistribution and EIGRP


Configuring RedistributionConfiguring

Redistribution


Configuring Redistribution

What do I need to determinebefore configuring redistribution?

• Identify the boundary routers where the protocols will run




• Determine which protocol is the core and which is the edge





• Determine which protocol is the core and which is the edge

• Determine the directions you want to redistribute the protocols



Configuring Redistribution into OSPF

RtrA(config-router)#router ospf 1RtrA(config-router)#redistribute eigrp ? <1-65535> Autonomous system numberRtrA(config-router)#redistribute eigrp 100 ? metric Metric for redistributed routes metric-type OSPF/IS-IS exterior metric type for redistributed routes route-map Route map reference subnets Consider subnets for redistribution into OSPF tag Set tag for routes redistributed into OSPF <cr>


Configuring Redistribution into EIGRP

Configuring Redistribution into EIGRP

RtrA(config-router)#router eigrp 100RtrA(config-router)#redistribute ospf ? <1-65535> Process ID

RtrA(config-router)#redistribute ospf 1 ? match Redistribution of OSPF routes metric Metric for redistributed routes route-map Route map reference <cr>


• Used for redistributing into OSPF, RIP, EGP, or BGP

Configuring default-metric

Router(config-router)#

default-metric bandwidth delay reliability loading mtu


default-metric number

• Used for redistributing into IGRP or EIGRP



Edge Protocol

Core Protocol

Redistribute

Default or Static

Redistribute and Change Administrative Distance

Redistribute and Filter



• Prevents routing protocol updates from being generated on the interface

passive-interface type number

Using and Configuring passive-interface


Router(config)#

ip route prefix mask address [distance ] [tag tag] [permanent]

Router(config)#

ip route prefix mask interface [distance ] [tag tag] [permanent]

Using and Configuring Static Routes

• Defines a path using an interface

• Use if you do not have a route to the next-hop address

• Automatically redistributed in some cases

• Defines a path using a next-hop address

• Use if you have a route to the defined address

• Requires redistribution


router rip passive-interface Serial1 network 10.0.0.0!ip route 172.16.0.0 255.255.0.0 Serial1

p1r2#sh ip route<Output Omitted>Gateway of last resort is not set

10.0.0.0 255.255.255.0 is subnetted, 2 subnetsC 10.1.3.0 is directly connected, Serial1C 10.1.1.0 is directly connected, Serial0S 172.16.0.0 is directly connected, Serial1<Output Omitted>

172.16.0.0

10.1.0.0

p2r2

p1r2

Static Route Example


Using and Configuring default-network

172.31.0.0/2410.1.0.0/24

p2r2p1r3

10.64.0.1/24

10.64.0.2/24

p1r3#show ip route<Output Omitted>Gateway of last resort is 10.64.0.2 to network 0.0.0.0 10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks<Output Omitted>R 10.2.3.0/24 [120/1] via 10.64.0.2, 00:00:05, Ethernet0C 10.64.0.0/24 is directly connected, Ethernet0R 172.31.0.0/16 [120/1] via 10.64.0.2, 00:00:16, Ethernet0R* 0.0.0.0/0 [120/1] via 10.64.0.2, 00:00:05, Ethernet0

p2r2:router rip network 10.0.0.0 network 172.31.0.0!ip classlessip default-network 10.0.0.0


Redistribution Example Using ip default-network

P1R3

S0:10.1.1.2/24

S1:10.1.1.1/24

S1:10.1.3.1/24S0:10.1.3.2/24

S0:10.1.2.1/24 S1:10.1.2.2/24

E0:172.6.31.5/24

E0:172.6.31.6/24

RIP

S1:10.2.1.1/24

S0:10.2.2.1/24

S1:10.2.2.2/24OSPF

S0:10.2.1.2/24

S1:10.2.3.1/24 S0:10.2.3.2/24

RIP

P1R1

P1R2

P2R3

P2R1

P2R2


Redistribution Example Using ip default-network (cont.)

P1R3-Boundary RouterP1R1-Internal

interface Serial0 ip address 10.1.2.1 255.255.255.0 bandwidth 64!interface Serial1 ip address 10.1.1.1 255.255.255.0 clockrate 56000!<Output Omitted>!router rip network 10.0.0.0!ip classless<Output Omitted>

<Output Omitted>!router ospf 200 redistribute rip metric 30 subnets network 172.6.31.5 0.0.0.0 area 0!router rip network 10.0.0.0!ip classlessip default-network 10.0.0.0!<Output Omitted>

Must Be On All RIP/IGRP Routers if Want to Use Default Route to Get to Unknown Subnets of Directly Connected Networks

Must Be Enabled for Subnets.Must Be Enabled for Subnets.



Boundary Router IP Routing Table

P1R3#show ip route

* 10.0.0.0/24 is subnetted, 6 subnetsC 10.1.3.0 is directly connected, Serial0O E2 10.2.1.0 [110/30] via 172.6.31.6, 00:44:56, Ethernet0C 10.1.2.0 is directly connected, Serial1R 10.1.1.0 [120/1] via 10.1.3.1, 00:00:05, Serial0 [120/1] via 10.1.2.1, 00:00:17, Serial1O E2 10.2.2.0 [110/30] via 172.6.31.6, 00:44:56, Ethernet0O E2 10.2.3.0 [110/30] via 172.6.31.6, 00:44:56, Ethernet0 172.6.0.0/24 is subnetted, 1 subnetsC 172.6.31.0 is directly connected, Ethernet0

RIP OSPFP1R3



Internal Router IP Routing Table

P1R1#show ip route<Output Omitted>

10.0.0.0/24 is subnetted, 3 subnetsR 10.1.3.0 [120/1] via 10.1.1.2, 00:00:24, Serial1 [120/1] via 10.1.2.2, 00:00:10, Serial0C 10.1.2.0 is directly connected, Serial0C 10.1.1.0 is directly connected, Serial1R* 0.0.0.0/0 [120/1] via 10.1.2.2, 00:00:10, Serial0

P1R1

RIP

• Router forwards packets destined to 10.2.0.0/24 networks using the default route


Controlling Routing Update

Traffic

Controlling Routing Update

Traffic


Redistribution Implementation Guidelines

IGRP/OSPF

IGRP OSPFRedistribute

Default or Static

IGRP OSPFRedistribute

Redistribute and Filter or Change Administrative Distance


Controlling Routing Update Traffic

How can we preventrouting update traffic from crossing some of these links?

172.16.7.1

172.16.7.2

172.16.6.1172.16.6.2

172.16.5.2

172.16.4.1

172.16.4.2

172.16.1.1

172.16.1.2172.16.3.1

172.16.3.2 172.16.2.2

172.16.2.1

172.16.9.1 172.16.10.1

172.16.11.1

Trans

R200 Cen

R300R100R100

Rem

172.16.12.1

64Kb

64Kb

T-1

T-1Frame Relay

172.16.5.1T-1

Frame Relay


Using Route Filters

Routingupdate


Using Route Filters

Determineinterface

Routingupdate


Using Route Filters

Is there a filter for thisinterface?

Determineinterface

Routingupdate


Using Route Filters

Yes

No

Process packet normally

End

Is there anentry for this

address?

No

Drop packet


Determineinterface

Routingupdate


Using Route Filters

Process entry according to filter

configuration

End

YesYes

No

Process packet normally

End

Is there anentry for this

address?

No

Drop packet


Determineinterface

Routingupdate


• Use a standard access list to permit or deny routes

• Access list can be applied to transmitted (outbound) or received (inbound) routing updates


distribute-list {access-list-number | name } out [interface-name | routing-process | autonomous-system number]

Configuring Route Filtering


distribute-list {access-list-number | name } in [type number]

For Outbound Updates:

For Inbound Updates:


• Hides network 10.0.0.0 using interface filtering

IP Route Filtering Configuration Example

S0 192.168.5.0

172.16.0.0

10.0.0.0

router eigrp 1

network 172.16.0.0

network 192.168.5.0

distribute-list 7 out s0

!

access-list 7 permit 172.16.0.0 0.0.255.255

router eigrp 1

network 172.16.0.0

network 192.168.5.0

distribute-list 7 out s0

!

access-list 7 permit 172.16.0.0 0.0.255.255

A

B


D E

IP Static Route Filtering Configuration Example

ip route 10.0.0.0 255.0.0.0 192.168.7.9ip route 172.16.0.0 255.255.0.0 192.168.7.5!router eigrp 1 network 192.168.7.0 default-metric 10000 100 255 1 1500 redistribute static distribute-list 3 out static!access-list 3 permit 10.0.0.0 0.255.255.255

passive-interface s0

192.168.7.4

S0

192.168.7.8

B

10.0.0.0172.16.0.0

passive-interface s0

192.168.7.12 192.168.7.16

S0A B C

D E


• Used for all protocols except EIGRP and BGP redistribution

• Used for EIGRP redistribution

Modifying Administrative Distance


distance weight [address mask [access-list-number | name ]] [ ip ]


distance eigrp internal-distance external-distance


Redistribution Example Using distance

172.16.7.1

172.16.7.2

172.16.6.1172.16.6.2

172.16.5.2

172.16.5.1172.16.4.1

172.16.4.2

172.16.1.1 172.16.1.2

172.16.3.1

172.16.3.2172.16.2.2

172.16.2.1

172.16.9.1 172.16.10.1

172.16.11.1

Trans

R200 Cen

Rem

172.16.12.1

64 kbps

64 kbps

T1

T1Frame Relay

S0.1S0.2

T1Frame Relay

R300 R100


Redistribution Example Using distance (cont.)

AdministrativeDistance

Metric

Cen#show ip route<Output Omitted>

172.16.0.0/24 is subnetted, 11 subnetsI 172.16.9.0 [100/158813] via 172.16.1.1, 00:00:02, TokenRing1I 172.16.10.0 [100/8976] via 172.16.5.2, 00:00:02, Serial0.1I 172.16.11.0 [100/8976] via 172.16.4.2, 00:00:02, Serial0.2C 172.16.4.0 is directly connected, Serial0.2C 172.16.5.0 is directly connected, Serial0.1I 172.16.6.0 [100/160250] via 172.16.5.2, 00:00:02, Serial0.1I 172.16.3.0 [100/8539] via 172.16.2.2, 00:00:02, TokenRing0 [100/8539] via 172.16.1.1, 00:00:03, TokenRing1

Cen

IGRP

With Only IGRP Running Everywhere:


172.16.7.1

172.16.7.2

172.16.6.1172.16.6.2

172.16.5.2

172.16.5.1172.16.4.1

172.16.4.2

172.16.1.1 172.16.1.2

172.16.3.1

172.16.3.2172.16.2.2

172.16.2.1

172.16.9.1 172.16.10.1

172.16.11.1

Trans

R200 Cen

Rem

172.16.12.1

64 kbps

64 kbps

T1

T1Frame Relay

S0.1S0.2

T1Frame Relay

R300 R100

IGRP

RIP




Router Cen Router R200

router rip redistribute igrp 1 passive-interface Serial0.2 passive-interface TokenRing0 passive-interface TokenRing1 network 172.16.0.0 default-metric 3!router igrp 1 redistribute rip passive-interface Serial0.1 network 172.16.0.0 default-metric 10 100 255 1 1500

router rip redistribute igrp 1 passive-interface Serial0 passive-interface TokenRing0 network 172.16.0.0 default-metric 3!router igrp 1 redistribute rip passive-interface Serial1 network 172.16.0.0 default-metric 10 100 255 1 1500


• Router Cen has RIP and IGRP routes

Cen#show ip route<Output Omitted>

172.16.0.0/24 is subnetted, 11 subnetsR 172.16.9.0 [120/2] via 172.16.5.2, 00:00:01, Serial0.1R 172.16.10.0 [120/1] via 172.16.5.2, 00:00:02, Serial0.1I 172.16.11.0 [100/8976] via 172.16.4.2, 00:00:02, Serial0.2C 172.16.4.0 is directly connected, Serial0.2C 172.16.5.0 is directly connected, Serial0.1R 172.16.6.0 [120/1] via 172.16.5.2, 00:00:02, Serial0.1I 172.16.3.0 [100/8539] via 172.16.2.2, 00:00:02, TokenRing0 [100/8539] via 172.16.1.1, 00:00:02, TokenRing1

IGRPWith IGRP and RIP Running:

RIPCen




172.16.7.1

172.16.7.2

172.16.6.1172.16.6.2

172.16.5.2

172.16.5.1172.16.4.1

172.16.4.2

172.16.1.1 172.16.1.2

172.16.3.1

172.16.3.2172.16.2.2

172.16.2.1

172.16.9.1 172.16.10.1

172.16.11.1

Trans

R200 Cen

Rem

172.16.12.1

64 kbps

64 kbps

T1

T1Frame Relay

S0.1S0.2

T1Frame Relay

R300 R100

IGRP

RIP


R200#show ip route<Output Omitted>

Gateway of last resort is not set

172.16.0.0/24 is subnetted, 11 subnetsI 172.16.9.0 [100/1000163] via 172.16.1.2, 00:00:37, TokenRing0I 172.16.10.0 [100/1000163] via 172.16.1.2, 00:00:37, TokenRing0I 172.16.11.0 [100/9039] via 172.16.1.2, 00:00:37, TokenRing0I 172.16.4.0 [100/8539] via 172.16.1.2, 00:00:37, TokenRing0I 172.16.5.0 [100/8539] via 172.16.1.2, 00:00:37, TokenRing0I 172.16.6.0 [100/1000163] via 172.16.1.2, 00:00:37, TokenRing0C 172.16.3.0 is directly connected, Serial0


• Router R200 includes suboptimal paths

R200R200RIP IGRPWith IGRP and RIP Running:



Router R200router rip redistribute igrp 1<Output Omitted> network 172.16.0.0 default-metric 3!router igrp 1 redistribute rip <Output Omitted> network 172.16.0.0 default-metric 10 100 255 1 1500 distance 130 0.0.0.0 255.255.255.255 1! access-list 1 permit 172.16.9.0access-list 1 permit 172.16.10.0access-list 1 permit 172.16.6.0

Router Cenrouter rip redistribute igrp 1<Output Omitted> network 172.16.0.0 default-metric 3!router igrp 1 redistribute rip <Output Omitted> network 172.16.0.0 default-metric 10 100 255 1 1500 distance 130 0.0.0.0 255.255.255.255 1!access-list 1 permit 172.16.9.0access-list 1 permit 172.16.10.0access-list 1 permit 172.16.6.0



• Router R200 learns some RIP routes

R200#show ip route<Output Omitted>

172.16.0.0/24 is subnetted, 11 subnetsR 172.16.9.0 [120/1] via 172.16.7.1, 00:00:19, Serial1R 172.16.10.0 [120/2] via 172.16.7.1, 00:00:19, Serial1I 172.16.11.0 [100/9039] via 172.16.1.2, 00:00:49, TokenRing0I 172.16.4.0 [100/8539] via 172.16.1.2, 00:00:49, TokenRing0I 172.16.5.0 [100/8539] via 172.16.1.2, 00:00:49, TokenRing0R 172.16.6.0 [120/1] via 172.16.7.1, 00:00:19, Serial1C 172.16.3.0 is directly connected, Serial0

R200R200RIP IGRP

With IGRP and RIP Running and Filtering:


Verifying RedistributionOperation

Verifying RedistributionOperation


• Displays the contents of the IP routing table

• Traces the path a packet takes

show ip routeRouter#

Verifying Redistribution Operation

tracerouteRouter#


Written ExerciseWritten Exercise


Policy-Based Routing Using Route Maps

Policy-Based Routing Using Route Maps


Route Maps Route Maps

• Route maps are complex access lists:

– Lines in access lists statements in route maps

– Access-list number route-map name

– Addresses and masks in access lists match statements in route maps

– Statements in route maps are numbered

• Can insert and delete statements in a route map

• Can edit match conditions in a statement

– Route-map statement can modify matched route with set command


Route Map ConfigurationRoute Map Configuration

Router(config)#

route-map map-tag [permit | deny] [sequence-number]

• Defines the conditions for policy routing

Router(config-route-map)#

match {conditions}


set {actions}

• Defines the conditions to match

• Defines the action to be taken on a match


Route Map ExplanationRoute Map Explanation

route-map demo permit 10 match x y z match a set b set croute-map demo permit 20 match q set rroute-map demo permit 30


Policy-Based RoutingPolicy-Based Routing

• Allows you to implement policies that selectively cause packets to take different paths

• Can also mark traffic with different TOS

• Since Cisco IOS Release 11.0


Policy-Based Routing Benefits

Policy-Based Routing Benefits

• Source-based transit provider selection

–Different users go different ways

• Quality of service (QoS)

–Set precedence or TOS, used with queuing

• Cost savings

–Use high-cost links only when necessary

• Load sharing

–Use multiple paths based on traffic characteristics


PoliciesPolicies

• Applied to incoming packets

• Implemented using route maps

– Matching routes modified by set commands

– If match criteria met and route map specified permit

• Control routing as specified by the set action

– If match criteria met and route map specified deny

– Normal (destination based) routing

– If all sequences in the list checked and no matches

• Normal (destination based) routing


Policy Routing match CommandsPolicy Routing match Commands


match ip address {access-list-number | name} [...access-list-number | name]


match length min max

• Matches IP addresses for policy routing

• Matches Layer 3 length of packet for policy routing


Policy Routing set CommandsPolicy Routing set Commands


set interface type number [...type number]

• Defines interface to which output packets


set ip next-hop ip-address [...ip-address]

• Defines next hop to which output packets


Policy Routing set Commands(cont.)Policy Routing set Commands(cont.)


set default interface type number [...type number]

• Defines interface to output packets that have no explicit route to the destination


set ip default next-hop ip-address [...ip-address]

• Defines next hop to output packets that have no explicit route to the destination


Configuring Policy-Based Routing

Configuring Policy-Based Routing

Router(config-if)#

ip policy route-map map-tag

• Specify a route map to use for policy routing on an interface

Router(config-if)#

ip route-cache policy

• Enable fast-switched policy routing


Policy-Based Routing Example

Policy-Based Routing Example

S3:10.1.1.1

C

A

B

192.168.2.0

S1:172.17.1.1

S0:10.1.1.100S1:172.17.1.2

S2:172.16.1.2

S0:172.16.1.1

192.168.1.0

• Router A has a policy that packets from 192.168.2.1 go to Router C’s interface S1


Policy-Based Routing Example (cont.)

Policy-Based Routing Example (cont.)

RouterA(config)# interface Serial2RouterA(config-if)# ip address 172.16.1.2 255.255.255.0RouterA(config-if)# ip policy route-map testRouterA(config)#route-map test permit 10RouterA(config-route-map)#match ip address 1RouterA(config-route-map)#set ip next-hop 172.17.1.2RouterA(config-route-map)#exitRouterA(config)#access-list 1 permit 192.168.2.1 0.0.0.0


Verifying Policy-Based Routing





Router#

show ip policy

• Displays route maps configured on interfaces

Router#

show route-map [map-name]

• Displays a route map


Verifying Policy-Based Routing (cont.)

Verifying Policy-Based Routing (cont.)

Router#

debug ip policy

• Enables display of IP policy routing events Router#

traceroute

• Extended traceroute allows specification of source address

Router#

ping

• Extended ping allows specification of source address


Verifying Policy-Based Routing Examples

Verifying Policy-Based Routing Examples

RouterA#show ip policyInterface Route mapSerial2 test

RouterA#show route-maproute-map test, permit, sequence 10 Match clauses: ip address (access-lists): 1 Set clauses: ip next-hop 172.17.1.2 Policy routing matches: 3 packets, 168 bytes


Verifying Policy-Based Routing Examples (cont.)

Verifying Policy-Based Routing Examples (cont.)

RouterA#debug ip policyPolicy routing debugging is on

RouterA#show logging...11:50:51: IP: s=172.16.1.1 (Serial2), d=192.168.1.1 (Serial3), len 100, policy rejected -- normal forwarding...11:51:25: IP: s=192.168.2.1 (Serial2), d=192.168.1.1, len 100, policy match11:51:25: IP: route map test, item 10, permit11:51:25: IP: s=192.168.2.1 (Serial2), d=192.168.1.1 (Serial1), len 100, policyrouted11:51:25: IP: Serial2 to Serial1 172.17.1.2


Case StudyCase Study


RIP Domain, Metric = Hops1 Public Class C Supports

Unix W/S, Servers

RIP Domain, Metric = Hops1 Public Class C Supports

Unix W/S, Servers

OSPF Domain, Metric = Cost1 Public Class C Supports

Acquisition Policy

OSPF Domain, Metric = Cost1 Public Class C Supports

Acquisition PolicyPrivate Address SpaceNetwork 10.0.0.0

Private Address SpaceNetwork 10.0.0.0

T-3T-3

Case Study—Redistribution

JKL’s Acquisition AA’s New Acquisition

To JKL3

Fast EthernetEthernetSerial

D

F

H

G

IGRP Domain, Metric = Composite1 Private Class A Supports

Regional Campus Topology

IGRP Domain, Metric = Composite1 Private Class A Supports

Regional Campus Topology

B

C

A

E


Lab ExerciseLab Exercise


Summary

After completing this chapter, you should be able to perform the following tasks: • Select and configure the different ways to control

route update traffic

• Configure route redistribution in a network that does not have redundant paths between dissimilar routing processes

• Configure route redistribution in a network that has redundant paths between dissimilar routing processes


Summary (cont.)Summary (cont.)

• Resolve path selection problems that result in a redistributed network

• Verify route redistribution

• Configure policy-based routing using route maps

• Given a set of network requirements, configure redistribution between different routing domains and verify proper operation (within described guidelines) of your routers

• Given a set of network requirements, configure policy-based routing within your pod and verify proper operation (within described guidelines) of your routers


Review Questions

1. What is redistribution?

2. What is the default administrative distance for IGRP? For RIP? For OSPF?

3. When configuring a default metric for redistributed routes, the metric should be set to a value ________ than the largest metric within the AS.

4. What command is used for policy-based routing to establish criteria based on the packet length?


Review Questions (cont.)Review Questions (cont.)

5. What command is used to configure filtering of the routing update traffic from an interface? What command mode is this command entered in?

6. What does the following command do? distance 150 0.0.0.0 255.255.255.255 3

7. What are the benefits of policy-based routing?

8. Policy-based routing is applied to ________ packets?

© 2000, Cisco Systems, Inc. 9-1 Optimizing Routing Update Operation Chapter 9.

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Transcript of © 2000, Cisco Systems, Inc. 9-1 Optimizing Routing Update Operation Chapter 9.