BSCI30_NIL_Lab_Guide.pdf

8/11/2019 BSCI30_NIL_Lab_Guide.pdf

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BSCI

Building ScalableCisco InternetworksVersion 3.0

NIL Lab Guide


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Copyright 2006, Cisco Systems, Inc. All rights reserved.

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Copyright2006, NIL Data Communications Table of Contents I

Table of Contents

Configuring and Tuning EIGRP 1

Objective 1

Command List 3Detailed Instructions 4

Lab Topology 12

Addressing and Routing 13

Configuring and Tuning EIGRP Lab Solutions 15

Lab Solution 15

Configuring and Examining OSPF in a Single Area 17

Objective 17

Command List 19

Detailed Instructions 20

Lab Topology 30


Configuring and Examining OSPF in a Single Area Lab Solutions 33

Lab Solution 33

Configuring OSPF for Frame Relay Environment 37

Objective 37

Command List 39


Lab Topology 51


Configuring OSPF for Frame Relay Environment Lab Solutions 55

Lab Solution 55

Configuring a Multi-Area OSPF Network 57

Objective 57

Command List 59


Lab Topology 80


Configuring a Multi-Area OSPF Network Lab Solutions 83

Lab Solution 83

Configuring Integrated IS-IS in Multiple Areas 87

Objective 87

Command List 89


Lab Topology 97


Configuring Integrated IS-IS in Multiple Areas Lab Solutions 101

Lab Solution 101

Configuring Route Redistribution 105

Objective 105

Command List 107


Lab Topology 117


Configuring Route Redistribution Lab Solutions 121

Lab Solution 121

Configuring BGP 123


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II Building Scalable Cisco Internetworks (BSCI) v3.0 Copyright2006, NIL Data Communications

Objective 123

Command List 125


Lab Topology 138


Configuring BGP Lab Solutions 141

Lab Solution 141

Scaling BGP 143

Objective 143

Command List 145


Lab Topology 154


Scaling BGP Lab Solutions 159

Lab Solution 159

Configuring Multicast Routing 161

Objective 161

Command List 162


Lab Topology 172


Configuring Multicast Routing Lab Solutions 175

Lab Solution 175

Configuring IPv6 Addressing, OSPFv3 Routing, and IPv6 Tunnel 177

Objective 177

Command List 179


Lab Topology 192


Configuring IPv6 Addressing, OSPFv3 Routing, and IPv6 Tunnel Lab Solutions 195

Lab Solution 195


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BSCI

Configuring and TuningEIGRP

Objective

In this exercise, you will configure EIGRP routing in your network by enabling EIGRP on allWAN links (Frame Relay sub-interfaces) and all LAN links within your network as shown in thefollowing figure.

Figure 1: Basic EIGRP deployment

After configuring basic EIGRP routing, you will examine the established EIGRP adjacencies, theEIGRP topology table and observe the IP routing tables. The changes in the network are

propagated through the entire network, which can result in frequent routing table recalculations.To improve the stability, convergence speed and to reduce the routing overhead in your networkyou will configure manual summarization towards the core routers. Next, you will influenceEIGRP path selection by changing delay on certain links. Finally you will deploy EIGRP stub

feature and advertise default route via EIGRP to internal routers to further improve stability ofthe network.


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2 Configuring and Tuning EIGRP Copyright2006, NIL Data Communications

Figure 2: EIGRP with enhancements

In this laboratory exercise, you will complete these tasks:

Configure your routers with EIGRP routing protocol.

Explore the EIGRP query traffic.

Configure route summarization using EIGRP.

Announce a default route via EIGRP routing protocol.

Configure the EIGRP stub feature to limit the scope of the EIGRP queries.

Note Please refer to the Topology sectionfor more details on physical connectivity and to the

Addressing section for detailed IP addressing information.


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Copyright2006, NIL Data Communications Configuring and Tuning EIGRP 3

Command List

Use the following commands to complete this exercise:

Command Task

bandwidth value Configures bandwidth in kbps on a certain interface.

debug ip eigrp Enables debugging of EIGRP.

delay value Configures delay in tens of microseconds on a certaininterface.

eigrp stub Configures a router to be an EIGRP stub router.

ip summary-address eigrpASnetwork mask

Configures an EIGRP per interface summary route(with the default Administrative Distance of 5).

network network {wildcard} Enables EIGRP on interfaces belonging to a specifiednetwork.

no auto-summary Disables the EIGRP automatic summarization on

classful network boundariesno shutdown Enables the interface.

router eigrp as-number Starts an EIGRP routing process with the given ASnumber.

show ip eigrp neighbors {detail} Lists EIGRP neighbors and relevant information onEIGRP neighbor adjacencies.

show ip eigrp topology [prefix][mask]

Displays EIGRP topology table (whole, or only perprefix/mask).

show ip protocols Displays the information about configured IPprotocols.

show ip route {network mask} Displays the IP routing table information (whole, or

only for specific network).

Shutdown Disables the interface.

undebug all Turns off all debugging.

Table 1: Configuration and monitoring commands used in the Configuring andTuning EIGRP Lab exercise


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Detailed Instructions

Task 1: Configuring Basic EIGRP

In this task, you will enable EIGRP in your network and examine the EIGRP query packets.

Step 1 Enable EIGRP routing protocol onR1,R2,R3andR4routers on all interfaces. Use the EIGRPAS number 1.

Step 2 Disable the auto summarization on all routers.

Step 3 Set the bandwidth of all serial interfaces on routersR1, R2, R3 and R4 to 64 kbps.

Note The routers in different lab pods may support only Ethernet or only FastEthernet interfaces. As

all printouts in the lab were taken on routers with FastEthernet interfaces, the default

bandwidth and the default delay on Ethernet interfaces were changed to FastEthernet

interface default values for compatibility reasons.

Verification

Step 4 Verify the configuration of your routers using the show ip protocols command. Assure that thecorrect AS number is configured and that the routers are exchanging routing updates with allneighbors. The command also reveals whether automatic summarization is enabled, the currentvalues of K weights, and administrative distance of internal and external EIGRP routes. Theexemplary printouts show the EIGRP information onR1 andR3 routers.

R1#show ip protocolsRouting Protocol is "eigrp 1"

Outgoing update filter list for all interfaces is not setIncoming update filter list for all interfaces is not set

Default networks flagged in outgoing updatesDefault networks accepted from incoming updates

EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0

EIGRP maximum hopcount 100

EIGRP maximum metric variance 1

Redistributing: eigrp 1

Automatic network summarization is not in effect

Maximum path: 4

Routing for Networks:

10.0.0.0

172.31.0.0

Routing Information Sources:

Gateway Distance Last Update(this router) 90 00:01:41

10.1.1.3 90 00:00:42

10.1.0.2 90 00:00:41

172.31.1.3 90 00:00:41

Distance: internal 90 external 170

Printout 1: EIGRP protocol information on R1router

R3#show ip protocols

Routing Protocol is "eigrp 1"Outgoing update filter list for all interfaces is not set

Incoming update filter list for all interfaces is not setDefault networks flagged in outgoing updates

Default networks accepted from incoming updates

EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0EIGRP maximum hopcount 100EIGRP maximum metric variance 1

Redistributing: eigrp 1


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Automatic network summarization is not in effect

Maximum path: 4

Routing for Networks:

10.0.0.0

Routing Information Sources:

Gateway Distance Last Update

10.1.1.1 90 00:01:43

10.1.3.4 90 00:01:43

Distance: internal 90 external 170

Printout 2: EIGRP protocol information on R3router

Step 5 Verify the establishment of EIGRP neighbor relations by using the show ip eigrp neighborscommand on all routers. The output also shows through which interfaces the router hasestablished EIGRP neighbor relations and the time that has elapsed since the individual EIGRPadjacency was established.

R2#show ip eigrp neighbors

IP-EIGRP neighbors for process 1

H Address Interface Hold Uptime SRTT RTO Q Seq

Type

(sec) (ms) Cnt Num

2 172.31.1.3 Se0/0.2 158 00:03:56 973 5000 0 6

1 10.1.2.4 Fa0/0 11 00:04:08 3 200 0 6

0 10.1.0.1 Se0/0.1 13 00:04:39 556 3336 0 9

Printout 3: EIGRP adjacencies on R2 router

Note The order of listed EIGRP neighbors depends on the time of adjacency establishment. The

most recent neighbor is on top (see Uptime column).

Step 6 Examine the routing table onR2andR4routers. Since auto summarization has been turned offand EIGRP is a classless routing protocol, routers learn of each subnet in your network.

R2#show ip route

...

Gateway of last resort is not set

172.31.0.0 255.255.255.0 is subnetted, 1 subnets

C 172.31.1.0 is directly connected, Serial0/0.210.0.0.0 255.255.255.0 is subnetted, 5 subnets

D 10.1.3.0 [90/40514560] via 10.1.2.4, 00:11:41, FastEthernet0/0C 10.1.2.0 is directly connected, FastEthernet0/0

D 10.1.1.0 [90/40514560] via 10.1.0.1, 00:11:41, Serial0/0.1C 10.1.0.0 is directly connected, Serial0/0.1

D 10.254.0.0 [90/41024000] via 172.31.1.3, 00:11:41, Serial0/0.2

Printout 4: Routing table on R2router

R4#show ip route

...



D 172.31.1.0 [90/40514560] via 10.1.2.2, 00:19:59, FastEthernet0/0


C 10.1.3.0 is directly connected, Serial0/0.1

C 10.1.2.0 is directly connected, FastEthernet0/0

D 10.1.1.0 [90/40514560] via 10.1.3.3, 00:19:59, Serial0/0.1



Printout 5: Routing table on R4 router

Step 7 Telnetto theBBR1router and examine the content of the routing and topology table.BBR1

knows about each and every subnet in your network. Since EIGRP supports equal-cost loadsharing by default, you should see that the networks 10.1.3.0/24 and 10.1.0.0/24 are accessiblevia two equal-cost next-hops. The output should be similar to the printout below.


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BBR1#show ip route

...





D 10.1.3.0 [90/41026560] via 172.31.1.1, 00:21:11, Serial0/0.2

[90/41026560] via 172.31.1.2, 00:21:11, Serial0/0.2D 10.1.2.0 [90/40514560] via 172.31.1.2, 00:21:11, Serial0/0.2

D 10.1.1.0 [90/40514560] via 172.31.1.1, 00:21:11, Serial0/0.2

D 10.1.0.0 [90/41024000] via 172.31.1.1, 00:21:11, Serial0/0.2

[90/41024000] via 172.31.1.2, 00:21:12, Serial0/0.2


Printout 6: Routing table on BBR1 router

BBR1#show ip eigrp topology

IP-EIGRP Topology Table for AS(1)/ID(10.254.0.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,r - reply Status, s - sia Status

P 10.1.3.0 255.255.255.0, 2 successors, FD is 41026560via 172.31.1.2 (41026560/40514560), Serial0/0.2via 172.31.1.1 (41026560/40514560), Serial0/0.2

P 10.1.2.0 255.255.255.0, 1 successors, FD is 40514560via 172.31.1.2 (40514560/28160), Serial0/0.2

P 10.1.1.0 255.255.255.0, 1 successors, FD is 40514560via 172.31.1.1 (40514560/28160), Serial0/0.2

P 10.1.0.0 255.255.255.0, 2 successors, FD is 41024000

via 172.31.1.2 (41024000/40512000), Serial0/0.2

via 172.31.1.1 (41024000/40512000), Serial0/0.2


via Connected, Serial0/0.2


via Connected, Serial0/0.1

BBR1#

Printout 7: EIGRP topology table on BBR1 router

The EIGRP topology table entry for the network 10.1.0.0/24 onBBR1router shows the vectormetric related with the destination.

BBR1#show ip eigrp topology 10.1.0.0 255.255.255.0

IP-EIGRP (AS 1): Topology entry for 10.1.0.0 255.255.255.0State is Passive, Query origin flag is 1, 2 Successor(s), FD is

41024000Routing Descriptor Blocks:

172.31.1.2 (Serial0/0.2), from 172.31.1.2, Send flag is 0x0Composite metric is (41024000/40512000), Route is Internal

Vector metric:Minimum bandwidth is 64 Kbit

Total delay is 40000 microsecondsReliability is 255/255

Load is 1/255Minimum MTU is 1500

Hop count is 1172.31.1.1 (Serial0/0.2), from 172.31.1.1, Send flag is 0x0

Composite metric is (41024000/40512000), Route is InternalVector metric:

Minimum bandwidth is 64 KbitTotal delay is 40000 microseconds

Reliability is 255/255

Load is 1/255

Minimum MTU is 1500

Hop count is 1

Printout 8: EIGRP topology table information for the 10.1.0.0/24 network onBBR1router


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Step 8 Use the debug ip eigrpcommand to monitor EIGRP queries onR4 internal router. Shut downthe S0/0.1 interface onR2router and observe EIGRP queries sent toR4router.R2queries for thenetwork 10.1.0.0/24R4and informsR4that it cannot reach that network (metric 4294967295signifies that the network is no longer reachable viaR2).R4queriesR3about that network andgets reply that the network is accessible viaR3.R4responds toR2that the network 10.1.0.0/24 isreachable andR2updates its routing table with the information about 10.1.0.0/24 network.

R4#debug ip eigrp

IP-EIGRP Route Events debugging is onR4#07:50:04: IP-EIGRP: Processing incoming QUERY packet

07:50:04: IP-EIGRP: Int 10.1.0.0 255.255.255.0 M 4294967295 - 04294967295 SM 4294967295 - 0 4294967295

(received query packet from R2 for lost networks 10.1.1.0/24 and10.1.0.0/24)

07:50:04: IP-EIGRP: Int 10.1.1.0 255.255.255.0 M 4294967295 - 400000004294967295 SM 4294967295 - 40000000 4294967295

07:50:04: IP-EIGRP: 10.1.0.0 255.255.255.0 - do advertise out Serial0/0.107:50:04: IP-EIGRP: Int 10.1.0.0 255.255.255.0 metric 4294967295 - 0

4294967295 (R4 has no Feasible Successor for 10.1.0.0, sends QUERY to R3)07:50:04: IP-EIGRP: Processing incoming REPLY packet

07:50:04: IP-EIGRP: Int 10.1.0.0 255.255.255.0 M 41026560 - 400000001026560 SM 40514560 - 40000000 514560

(Received REPLY from R3 with valid information)07:50:04: IP-EIGRP: 10.1.0.0 255.255.255.0 routing table not updated

07:50:04: IP-EIGRP: 10.1.0.0 255.255.255.0 routing table not updated07:50:04: IP-EIGRP: Int 10.1.0.0 255.255.255.0 metric 41026560 - 40000000

102656007:50:05: IP-EIGRP: 10.1.1.0 255.255.255.0 - do advertise out

FastEthernet0/0

07:50:05: IP-EIGRP: Int 10.1.1.0 255.255.255.0 metric 40514560 - 40000000

514560

07:50:05: IP-EIGRP: 10.1.0.0 255.255.255.0 - do advertise out

FastEthernet0/0 (advertising update on 10.1.0.0 network to R2, based on

reply from R3)07:50:05: IP-EIGRP: Int 10.1.0.0 255.255.255.0 metric 41026560 - 40000000

1026560

Printout 9: EIGRP debug output on R4router

Note The text in italics is a comment added to the output to aid the output explanation and will not

be present in your output.

R2#show ip route

...



C 172.31.1.0 is directly connected, Serial0/0.210.0.0.0 255.255.255.0 is subnetted, 5 subnets


C 10.1.2.0 is directly connected, FastEthernet0/0D 10.1.1.0 [90/40517120] via 10.1.2.4, 00:02:37, FastEthernet0/0D 10.1.0.0 [90/41029120] via 10.1.2.4, 00:02:37, FastEthernet0/0

D 10.254.0.0 [90/41024000] via 172.31.1.3, 00:04:27, Serial0/0.2


Step 9 Disable the debugging of the EIGRP operation onR4router and re-enable the connectionbetweenR1andR2edge routers.


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Task 3: Improve EIGRP Core Scalability

In this task, you will configure the EIGRP manual route summarization. Summarizationimproves convergence speed and network stability by controlling the scope of queries andminimizing the amount of routing update traffic and the size of the routing table.

Step 13 Configure manual summarization onR1andR2edge routers. Summarize the internal networkstowards the core into a single 10.1.0.0/16 network.

Verification

Step 14 TelnettoBBR1router and re-examine the routing and topology tables.BBR1router no longerhas knowledge about 10.1.0.0/24, 10.1.1.0/24, 10.1.2.0/24 and 10.1.3.0/24 subnets. Instead, onlysummary route 10.1.0.0/16 is known and thus the routing and topology tables are smaller due tosummarization. Notice that there are two equal-cost paths to 10.1.0.0/16 network, soBBR1will

perform load sharing for all 10.1.0.0/16 subnets.

BBR1#show ip route

...




10.0.0.0 255.0.0.0 is variably subnetted, 2 subnets, 2 masks

D 10.1.0.0 255.255.0.0

[90/2172416] via 172.31.1.1, 00:01:20, Serial0/0.2

[90/2172416] via 172.31.1.2, 00:01:20, Serial0/0.2

C 10.254.0.0 255.255.255.0 is directly connected, Serial0/0.1

BBR1#

Printout 13: Routing table on BBR1router

BBR1#show ip eigrp topology 10.1.0.0 255.255.0.0

IP-EIGRP (AS 1): Topology entry for 10.1.0.0 255.255.0.0

State is Passive, Query origin flag is 1, 2 Successor(s), FD is 2172416Routing Descriptor Blocks:

172.31.1.2 (Serial0/0.2), from 172.31.1.2, Send flag is 0x0

Composite metric is (2172416/28160), Route is Internal

Vector metric:

Minimum bandwidth is 1544 Kbit

Total delay is 20100 microseconds


Load is 1/255

Minimum MTU is 1500

Hop count is 1

172.31.1.1 (Serial0/0.2), from 172.31.1.1, Send flag is 0x0

Composite metric is (2172416/28160), Route is Internal

Vector metric:

Minimum bandwidth is 1544 KbitTotal delay is 20100 microseconds


Load is 1/255

Minimum MTU is 1500

Hop count is 1

Printout 14: EIGRP topology table information for 10.1.0.0/16 network on BBR1router

Step 15 Check the routing table ofR1andR2routers. The propagation of a summary route results in anunconditional attraction of the traffic for all the subnets from the summary, even if a particularsubnet does not exist anymore. To avoid black holing the traffic or even creating routing loops,EIGRP installs a summary route connected to the Null0 interface onR1 andR2 routers. So, in

case a router receives packets destined for a subnet that does not exist, such packets are routed tothe Null0 interface, in other words, they are dropped.


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R2#show ip route 10.1.0.0 255.255.0.0

Routing entry for 10.1.0.0 255.255.0.0

Known via "eigrp 1", distance 5, metric 28160, type internal

Redistributing via eigrp 1

Routing Descriptor Blocks:

* directly connected, via Null0

Route metric is 28160, traffic share count is 1

Total delay is 100 microseconds, minimum bandwidth is 100000 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 1/255, Hops 0Printout 15: Routing table on BBR1router

Task 4: Configure EIGRP Stub

Your job now is to limit the query traffic from edge routers to internal routers. You willaccomplish that by deploying the EIGRP stub feature, which improves convergence speed andnetwork stability and helps avoiding stuck in active (SIA) situations, where EIGRP is unable toresolve routes for long periods.

Step 16 ConfigureR3andR4internal routers as EIGRP stubs.

Verification

Step 17 Examine the detailed EIGRP neighbor information with the show ip eigrp neighbors detailcommand onR1andR2router.R1router recognizesR3router as an EIGRP stub andR2routerrecognizesR4router as an EIGRP stub.

R1#show ip eigrp neighbors detail



Type(sec) (ms) Cnt Num

2 10.1.1.3 Fa0/0 12 00:00:16 403 2418 0 66

Version 12.2/1.2, Retrans: 0, Retries: 0

Stub Peer Advertising ( CONNECTED SUMMARY ) Routes

0 172.31.1.3 Se0/0.2 162 00:07:02 46 2280 0 53


1 10.1.0.2 Se0/0.1 14 00:24:04 36 2280 0 212


Printout 16: Detailed EIGRP neighbor information on R1router

R2#show ip eigrp neighbors detail



Type(sec) (ms) Cnt Num

1 10.1.2.4 Fa0/0 11 00:01:25 3 200 0 131


Stub Peer Advertising ( CONNECTED SUMMARY ) Routes

0 172.31.1.3 Se0/0.2 161 00:06:53 40 2280 0 52


2 10.1.0.1 Se0/0.1 11 00:24:50 38 2280 0 152


Printout 17: Detailed EIGRP neighbor information on R2router


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Step 18 To examine the benefits of EIGRP stub, enable EIGRP debugging onR4router with the debugip eigrp command. Shut down the S0/0.1 link betweenR1andR2routers. Notice that no queriesare now being sent to theR4internal router.

R4#debug ip eigrp

IP-EIGRP Route Events debugging is on

R4#

Printout 18: EIGRP debugging output on R4router

Step 19 Disable the debugging of EIGRP operation onR4router and re-enable the connection betweenR1andR2edge routers.

Task 5: Configuring the EIGRP Default Route

To further improve the stability and convergence speed, you will minimize the update traffic sentto internal routers and minimize their routing tables. To achieve that, you will announce only adefault route via EIGRP and filter all specific routes to internal routers

Step 20 Announce only a default route fromR1andR2edge routers toR3andR4internal routers byusing manual summarization.

Verification

Step 21 Check the routing table ofR3andR4routers. The routers have now learned only a default routefrom edge routers and connected routes from the other internal router. The more specific routesfrom edge routers have been filtered out by the summarization.

R3#show ip route

...

Gateway of last resort is 10.1.1.1 to network 0.0.0.0



D 10.1.2.0 [90/40514560] via 10.1.3.4, 00:45:30, Serial0/0.1

C 10.1.1.0 is directly connected, FastEthernet0/0

D* 0.0.0.0 0.0.0.0 [90/30720] via 10.1.1.1, 00:39:02, FastEthernet0/0


Review Questions

What is the default administrative distance for EIGRP?

__________________________________________________________________

What kind of load balancing does EIGRP support?

__________________________________________________________________

Which parameters does EIGRP use by default to calculate route metric?

__________________________________________________________________

What can be deployed to improve EIGRP scalability?

__________________________________________________________________


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Addressing and Routing

This section contains information on IP addressing ranges and EIGRP routing used in the remotelab.

Note IP addressing and core routing have been pre-configured to allow you to focus exclusively on

the objectives of the exercise.

IP Addressing Scheme

The addressing of lab exercise routers uses the following IP allocation scheme:

Parameter Value

WAN subnet between core and edge routers 172.31.1.0/24

Core network 10.254.0.0/24

LAN subnet between R1and R3 10.1.1.0/24

LAN subnet between R2and R4 10.1.2.0/24

R1to R2point-to-point connection 10.1.0.0/24

R3to R4point-to-point connection 10.1.3.0/24

Table 4: Network address space

The actual addresses used on WAN and LAN links configured on the Lab exercise routers aredisplayed in the following figure:

Figure 4: Addressing of Lab exercise routers

Note The address shown in a callout pointing to a router interface is the IP address configured on

that interface.


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Existing EIGRP Routing

EIGRP is used as the routing protocol between core BBR1 router and R1, R2 edge routers. Theexisting EIGRP routing configuration on BBR1 is shown below:

interface Serial 0/0.2 multipoint

bandwidth 64

no ip split-horizon eigrp 1!

router eigrp 1

network 10.254.0.0 0.0.0.255

network 172.31.0.0

no auto-summary

Printout 20: EIGRP routing on BBR1router


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Copyright2006, NIL Data Communications Configuring and Tuning EIGRP Lab Solutions 15

BSCI

Configuring and TuningEIGRP

Lab Solutions

Lab Solution

Task 1: Configuring Basic EIGRP

The following commands need to be entered onR1andR2 routers:

interface Serial0/0.1 point-to-point

bandwidth 64!

interface Serial0/0.2 multipointbandwidth 64

!router eigrp 1

network 10.0.0.0

network 172.31.1.0

no auto-summary

Configuration 1: EIGRP configuration on R1 and R2 routers


interface Serial0/0.1 point-to-pointbandwidth 64

!router eigrp 1

network 10.0.0.0

no auto-summary

Configuration 2: EIGRP configuration on R3 and R4 routers


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16 Configuring and Tuning EIGRP Lab Solutions Copyright2006, NIL Data Communications

Task 2: Influence EIGRP Path Selection

The following commands need to be entered onR1 router:


delay 2500

Configuration 3: Delay adjustment on R1 router

Task 3: Improve EIGRP Core Scalability

The following commands need to be entered onR1 andR2 routers:

interface Serial0/0.2 multipoint

ip summary-address eigrp 1 10.1.0.0 255.255.0.0

Configuration 4: EIGRP summarization on R1 and R2 routers

Task 4: Configuring EIGRP Stub


router eigrp 1

eigrp stub

Configuration 5: EIGRP stub configuration on R3 and R4 routers

Task 5: Configuring the EIGRP Default Route


interface FastEthernet0/0

ip summary-address eigrp 1 0.0.0.0 0.0.0.0

Configuration 6: EIGRP default route origination on R1 and R2 routers

Answers to Review Questions

Q1: What is the default administrative distance for EIGRP?

A1: EIGRP uses two values for administrative distance. Internal routes have administrative 90,external routes have administrative distance 170.

Q2: What kind of load balancing does EIGRP support?

A2: EIGRP supports equal-cost load balancing by default and non-equal-cost load balancing.

Q3: Which parameters does EIGRP use by default to calculate route metric?

A3: Bandwidth and delay.

Q4: What can be deployed to improve EIGRP scalability?

A4: EIGRP summarization and EIGRP stub feature.


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Copyright2006, NIL Data Communications Configuring and Examining OSPF in a Single Area 17

BSCI

Configuring and ExaminingOSPF in a Single Area

Objective

In this exercise, you will deploy OSPF routing in your network by enabling OSPF on all WANlinks (Frame Relay sub-interfaces) and all LAN links within your network as shown in thefollowing figure.

Figure 5: Basic OSPF deployment

You will improve the stability of OSPF operation by configuring loopback interfaces and OSPFrouter IDs. After configuring basic OSPF routing, you will examine the established OSPFadjacencies and IP routing tables and check the operation of OSPF.

Then you will reconfigure OSPF on LAN links to influence OSPF operation and DesignatedRouter (DR) election and observe the election process. Next you will fine tune the OSPF costs sothat the link betweenR3andR4routers will be used only in case of aR1toR2link failure.


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18 Configuring and Examining OSPF in a Single Area Copyright2006, NIL Data Communications

Figure 6: Influencing the primary/backup configuration


Configure your routers with OSPF routing protocol and stable OSPF router IDs.

Explore OSPF packet types.

Influence OSPF DR and BDR election on LAN.

Influence OSPF route selection by changing OSPF link cost.




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Task 1: Configuring Single Area OSPF

In this task, you will enable OSPF routing protocol in your network and examine the OSPFoperation.

Step 22 Enable OSPF with the process ID 1 on all interfaces on R3andR4routers. Place all interfaces inOSPF Area 0. To avoid problems in later tasks, use a network statement for 10.1.0.0 networkrather than the entire 10.0.0.0 network.

Step 23 Enable OSPF with the process ID 1 also on all interfaces onR1andR2routers. Place allinterfaces in OSPF Area 0. To avoid problems in later tasks, use a network statement for 10.1.0.0network rather than the entire 10.0.0.0 network.


all printouts in the lab were taken on routers with FastEthernet interfaces, the defaultbandwidth and the default delay on Ethernet interfaces were changed to FastEthernet

interface default values for compatibility reasons.

Note Enabling OSPF on an interface can be done by using the network router configuration

command or the ip ospfprocess-id area area-id interface configuration command available

since IOS 12.3(11)T.

Verification

Step 24 Verify that you have full connectivity within your network using the pingcommand. Make surethat you can pingall the other routers within your network.

Step 25 Examine the routing table of your routers. Since you have only one OSPF area, you will see onlyintra-area (O) OSPF routes. Using the show ip route command, you should see the outputssimilar to the following printouts:

R1#show ip route...


10.0.0.0 255.255.255.0 is subnetted, 4 subnetsO 10.1.3.0 [110/1563] via 10.1.1.3, 00:02:15, FastEthernet0/0

O 10.1.2.0 [110/1563] via 10.1.0.2, 00:02:15, Serial0/0.1C 10.1.1.0 is directly connected, FastEthernet0/0C 10.1.0.0 is directly connected, Serial0/0.1


R3#show ip route...


10.0.0.0 255.255.255.0 is subnetted, 4 subnetsC 10.1.3.0 is directly connected, Serial0/0.1O 10.1.2.0 [110/1563] via 10.1.3.4, 00:02:46, Serial0/0.1C 10.1.1.0 is directly connected, FastEthernet0/0

O 10.1.0.0 [110/1563] via 10.1.1.1, 00:02:46, FastEthernet0/0Printout 22: Routing table on R3router


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Step 26 Check OSPF router IDs on your routers using the show ip ospfcommand. The router ID is thehighest loopback IP address or the highest active IP address on the router. The command alsoreveals the OSPF areas that the router participates in and the number of interfaces in a certainarea.

R2#show ip ospfRouting Process "ospf 1" with ID 10.1.2.2Supports only single TOS(TOS0) routes

Supports opaque LSASPF schedule delay 5 secs, Hold time between two SPFs 10 secsMinimum LSA interval 5 secs. Minimum LSA arrival 1 secsNumber of external LSA 0. Checksum Sum 0x0Number of opaque AS LSA 0. Checksum Sum 0x0Number of DCbitless external and opaque AS LSA 0Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 1. 1 normal 0 stub 0 nssaExternal flood list length 0Area BACKBONE(0)

Number of interfaces in this area is 2Area has no authenticationSPF algorithm executed 3 timesArea ranges areNumber of LSA 6. Checksum Sum 0x2FF92Number of opaque link LSA 0. Checksum Sum 0x0

Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0

Printout 23: OSPF process information on R2router

Use the following table to write down OSPF router IDs of your routers.

Router Router ID

R1

R2

R3

R4

Table 1: Router IDs

Step 27 Check the established OSPF adjacencies on theR1router with the show ip ospf neighborcommand. The neighbors states ofR3andR2routers should be FULL and theR3router should

be the DR router on the Ethernet connection betweenR1andR3routers.

R1#show ip ospf neighbor

Neighbor ID Pri State Dead Time AddressInterface

10.1.2.2 1 FULL/ - 00:00:37 10.1.0.2Serial0/0.110.1.3.3 1 FULL/DR 00:00:36 10.1.1.3FastEthernet0/0

Printout 24: OSPF adjacency information on R1router


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Task 2: Configuring Stable OSPF Router ID

You must change Router IDs on your routers to achieve more stable OSPF operation. You willachieve that by configuring loopback interfaces on some routers and OSPF router IDs on otherrouters.

Step 28 Configure IP address 10.200.200.13/32 on loopback0 interface onR3router.

Step 29 Configure IP address 10.200.200.14/32 on loopback0 interface onR4router.

Step 30 Configure OSPF router ID 10.0.0.11 onR1router.

Step 31 Configure OSPF router ID 10.0.0.12 onR2router.

Note The ability to manually set the OSPF router ID was introduced in Cisco IOS Release 12.0(1)T.

Verification

Step 32 Check again the OSPF router IDs of all your routers and compare the values with the values fromthe previous task.

Notice that router IDs have not changed. This is a stability feature of a Cisco IOS. If router IDchanged, the link-state advertisements (LSAs) would be invalid and the routers would have to re-converge.

To change the router IDs on routersR3andR4, where you configured loopback addresses, youwould have to reload the router or disable and then re-enable the OSPF process.

To change the router IDs on routers R1 and R2, where you configured them manually, youwould have to reset the OSPF process as explained in the following steps.

R2#show ip ospfRouting Process "ospf 1" with ID 10.1.2.2Supports only single TOS(TOS0) routesSupports opaque LSASPF schedule delay 5 secs, Hold time between two SPFs 10 secsMinimum LSA interval 5 secs. Minimum LSA arrival 1 secsNumber of external LSA 0. Checksum Sum 0x0Number of opaque AS LSA 0. Checksum Sum 0x0Number of DCbitless external and opaque AS LSA 0Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 1. 1 normal 0 stub 0 nssaExternal flood list length 0Area BACKBONE(0)

Number of interfaces in this area is 2

Area has no authenticationSPF algorithm executed 3 timesArea ranges areNumber of LSA 6. Checksum Sum 0x2FF92Number of opaque link LSA 0. Checksum Sum 0x0Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 0

Printout 25: Unchanged router ID on R2 router

Step 33 Save the OSPF configuration onR3andR4routers to a text file and disable the OSPF on bothrouters using the no router ospf 1command. Use the saved OSPF configuration and apply theconfiguration back to your routers. Check the router IDs ofR3andR4routers. Notice that router

IDs have changed and are now set to the IP address of a loopback0 interface.


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R3#show ip ospfRouting Process "ospf 1" with ID 10.200.200.13Supports only single TOS(TOS0) routesSupports opaque LSASPF schedule delay 5 secs, Hold time between two SPFs 10 secsMinimum LSA interval 5 secs. Minimum LSA arrival 1 secsNumber of external LSA 0. Checksum Sum 0x0Number of opaque AS LSA 0. Checksum Sum 0x0Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 1. 1 normal 0 stub 0 nssaExternal flood list length 0Area BACKBONE(0)

Number of interfaces in this area is 2Area has no authenticationSPF algorithm executed 2 timesArea ranges areNumber of LSA 4. Checksum Sum 0x15ABDNumber of opaque link LSA 0. Checksum Sum 0x0Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 1

Printout 26: New router ID on R3router

Step 34 Reset the OSPF process with the clear ip ospf process command onR1andR2routers and thencheck the router IDs. The router IDs have changed to the manually configured values.

R1#show ip ospfRouting Process "ospf 1" with ID 10.0.0.11Supports only single TOS(TOS0) routesSupports opaque LSASPF schedule delay 5 secs, Hold time between two SPFs 10 secsMinimum LSA interval 5 secs. Minimum LSA arrival 1 secsNumber of external LSA 0. Checksum Sum 0x0Number of opaque AS LSA 0. Checksum Sum 0x0Number of DCbitless external and opaque AS LSA 0Number of DoNotAge external and opaque AS LSA 0Number of areas in this router is 1. 1 normal 0 stub 0 nssaExternal flood list length 0Area BACKBONE(0)

Number of interfaces in this area is 2Area has no authenticationSPF algorithm executed 14 timesArea ranges areNumber of LSA 9. Checksum Sum 0x38A27Number of opaque link LSA 0. Checksum Sum 0x0Number of DCbitless LSA 0Number of indication LSA 0Number of DoNotAge LSA 0Flood list length 4

Printout 27: New router ID on R1router

Step 35 Verify that OSPF adjacencies are in FULL state on all your routers.

Task 3: Understanding OSPF Packet Types

In this task, you will observe the creation of OSPF adjacency and packets that are exchangedupon neighbor relationship being established.


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Verification

Step 36 Shut down the Fe0/0 interface onR1router.

Step 37 Enable the debugging of OSPF events onR1router with the debug ip ospf events command toexamine OSPF packet types.

Step 38 Reset the OSPF process with the clear ip ospf process command and observe howR1establishes OSPF adjacency withR2router via S0/0.1 interface. The routers start exchangingOSPF hello packets and reach the 2-WAY OSPF state when they become aware of each other.

Next they have to agree on who will lead the exchange of DBD packets this is called theEXSTART state. In this case, the R2 router is a master since it has a higher router ID and R1router is a slave. Afterwards they trade the DBD packets and synchronize their view of the OSPFarea in the EXCHANGE state. The end of the OSPF adjacency establishment process is indicatedwith routers being in the OSPF FULL state.

R1#clear ip ospf processReset ALL OSPF processes? [no]: yesR1#10:24:24: OSPF: Flushing External Links10:24:24: OSPF: Flushing Opaque AS Links10:24:24: OSPF: Flushing Link states in area 010:24:24: OSPF: Interface Serial0/0.1 going Down10:24:24: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.12 on Serial0/0.1 fromFULL to DOWN, Neighbor Down: Interface down or detached10:24:24: OSPF: Interface Serial0/0.1 going Up10:24:24: OSPF: i_up : interface is down10:24:24: OSPF: Rcv hello from 10.0.0.12 area 0 from Serial0/0.1 10.1.0.210:24:24: OSPF: 2 Way Communication to 10.0.0.12 on Serial0/0.1, state2WAY10:24:24: OSPF: Send DBD to 10.0.0.12 on Serial0/0.1 seq 0xF80 opt 0x42flag 0x7 len 3210:24:24: OSPF: End of hello processing10:24:24: OSPF: Rcv DBD from 10.0.0.12 on Serial0/0.1 seq 0x1260 opt 0x42flag 0x7 len 32 mtu 1500 state EXSTART10:24:24: OSPF: NBR Negotiation Done. We are the SLAVE10:24:24: OSPF: Send DBD to 10.0.0.12 on Serial0/0.1 seq 0x1260 opt 0x42

flag 0x0 len 3210:24:24: OSPF: Rcv DBD from 10.0.0.12 on Serial0/0.1 seq 0x1261 opt 0x42flag 0x3 len 132 mtu 1500 state EXCHANGE10:24:24: OSPF: Send DBD to 10.0.0.12 on Serial0/0.1 seq 0x1261 opt 0x42flag 0x0 len 3210:24:24: OSPF: Database request to 10.0.0.1210:24:24: OSPF: sent LS REQ packet to 10.1.0.2, length 6010:24:24: OSPF: Rcv DBD from 10.0.0.12 on Serial0/0.1 seq 0x1262 opt 0x42flag 0x1 len 32 mtu 1500 state EXCHANGE10:24:24: OSPF: Exchange Done with 10.0.0.12 on Serial0/0.110:24:24: OSPF: Send DBD to 10.0.0.12 on Serial0/0.1 seq 0x1262 opt 0x42flag 0x0 len 3210:24:24: OSPF: Synchronized with 10.0.0.12 on Serial0/0.1, state FULL10:24:24: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.12 on Serial0/0.1 fromLOADING to FULL, Loading Done

Printout 28: R1to R2OSPF adjacencies establishment on R1router

Step 39 Shut down the S0/0.1 interface and re-enable the Fe0/0 onR1router.

Step 40 Reset the OSPF process with the clear ip ospf process command and observe howR1establishes OSPF adjacency withR3router via Fe0/0 interface. The establishment of OSPFadjacency is very similar to the previous case. The difference is that routers here elect OSPF DRand BDR router, since they peer over a broadcast network.

R1#clear ip ospf processReset ALL OSPF processes? [no]: yesR1#10:38:31: OSPF: Flushing External Links10:38:31: OSPF: Flushing Opaque AS Links

10:38:31: OSPF: Flushing Link states in area 010:38:31: OSPF: Interface FastEthernet0/0 going Down10:38:31: OSPF: Neighbor change Event on interface FastEthernet0/010:38:31: OSPF: DR/BDR election on FastEthernet0/010:38:31: OSPF: Elect BDR 0.0.0.0


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10:38:31: OSPF: Elect DR 10.200.200.1310:38:31: OSPF: Elect BDR 0.0.0.010:38:31: OSPF: Elect DR 10.200.200.1310:38:31: DR: 10.200.200.13 (Id) BDR: none10:38:31: %OSPF-5-ADJCHG: Process 1, Nbr 10.200.200.13 on FastEthernet0/0from FULL to DOWN, Neighbor Down: Interface down or detached10:38:31: OSPF: Neighbor change Event on interface FastEthernet0/010:38:31: OSPF: DR/BDR election on FastEthernet0/010:38:31: OSPF: Elect BDR 0.0.0.0

10:38:31: OSPF: Elect DR 0.0.0.010:38:31: DR: none BDR: none10:38:31: OSPF: Remember old DR 10.200.200.13 (id)10:38:31: OSPF: i_up : interface is down10:38:31: OSPF: Interface FastEthernet0/0 going Up10:38:36: OSPF: Rcv hello from 10.200.200.13 area 0 from FastEthernet0/010.1.1.310:38:36: OSPF: 2 Way Communication to 10.200.200.13 on FastEthernet0/0,state 2WAY10:38:36: OSPF: Backup seen Event before WAIT timer on FastEthernet0/010:38:36: OSPF: DR/BDR election on FastEthernet0/010:38:36: OSPF: Elect BDR 10.0.0.1110:38:36: OSPF: Elect DR 10.200.200.1310:38:36: OSPF: Elect BDR 10.0.0.1110:38:36: OSPF: Elect DR 10.200.200.13

10:38:36: DR: 10.200.200.13 (Id) BDR: 10.0.0.11 (Id)10:38:36: OSPF: Send DBD to 10.200.200.13 on FastEthernet0/0 seq 0x253Aopt 0x42 flag 0x7 len 3210:38:36: OSPF: End of hello processing10:38:36: OSPF: Rcv DBD from 10.200.200.13 on FastEthernet0/0 seq 0x103Eopt 0x42 flag 0x7 len 32 mtu 1500 state EXSTART10:38:36: OSPF: NBR Negotiation Done. We are the SLAVE10:38:36: OSPF: Send DBD to 10.200.200.13 on FastEthernet0/0 seq 0x103Eopt 0x42 flag 0x2 len 5210:38:36: OSPF: Rcv DBD from 10.200.200.13 on FastEthernet0/0 seq 0x103Fopt 0x42 flag 0x3 len 112 mtu 1500 state EXCHANGE10:38:36: OSPF: Send DBD to 10.200.200.13 on FastEthernet0/0 seq 0x103Fopt 0x42 flag 0x0 len 3210:38:36: OSPF: Database request to 10.200.200.1310:38:36: OSPF: sent LS REQ packet to 10.1.1.3, length 4810:38:36: OSPF: Rcv DBD from 10.200.200.13 on FastEthernet0/0 seq 0x1040

opt 0x42 flag 0x1 len 32 mtu 1500 state EXCHANGE10:38:36: OSPF: Exchange Done with 10.200.200.13 on FastEthernet0/010:38:36: OSPF: Send DBD to 10.200.200.13 on FastEthernet0/0 seq 0x1040opt 0x42 flag 0x0 len 3210:38:36: OSPF: Synchronized with 10.200.200.13 on FastEthernet0/0, stateFULL10:38:36: %OSPF-5-ADJCHG: Process 1, Nbr 10.200.200.13 on FastEthernet0/0from LOADING to FULL, Loading Done10:38:46: OSPF: Rcv hello from 10.200.200.13 area 0 from FastEthernet0/010.1.1.310:38:46: OSPF: Neighbor change Event on interface FastEthernet0/010:38:46: OSPF: DR/BDR election on FastEthernet0/010:38:46: OSPF: Elect BDR 10.0.0.1110:38:46: OSPF: Elect DR 10.200.200.1310:38:46: DR: 10.200.200.13 (Id) BDR: 10.0.0.11 (Id)

10:38:46: OSPF: End of hello processingPrintout 29: R1to R2OSPF adjacencies establishment on R1 router

Step 41 Disable the debugging of OSPF events onR1router and re-enable S0/0.1.


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Task 4: Understanding OSPF DR and BDR Elections

Now you will influence the election of DR and BDR routers on LAN by manually configuringthe OSPF priority on proper interfaces.

Step 42 First check the default OSPF priority and current DR on LAN network betweenR2andR4routers with the show ip ospf interfacecommand onR4router.R4 router is the OSPF DR andits default OSPF priority is 1:

R4#show ip ospf interface FastEthernet 0/0FastEthernet0/0 is up, line protocol is upInternet Address 10.1.2.4 255.255.255.0, Area 0Process ID 1, Router ID 10.200.200.14, Network Type BROADCAST, Cost: 1Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 10.200.200.14, Interface address 10.1.2.4Backup Designated router (ID) 10.0.0.12, Interface address 10.1.2.2Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:02

Index 1/1, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 2, maximum is 2Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 1, Adjacent neighbor count is 1Adjacent with neighbor 10.0.0.12 (Backup Designated Router)Suppress hello for 0 neighbor(s)

R4#

Printout 30: OSPF information for interface Fe0/0 on R4router

Step 43 Influence the election of DR by setting the OSPF priority to 0 on R4router LAN interface.Setting OSPF priority to 0 removes the router from the election process.

Verification

Step 44 Disable the Fe0/0 interface onR2andR4routers and S0/0.1interface onR4router. Enable thedebugging of OSPF events onR4router with debug ip ospf events command to examine OSPFDR election process.

Step 45 Enable the Fe0/0 interfaces onR2andR4routers and observe the election process. SinceR4router has OSPF priority set to 0,R2router is the only candidate for the role of the DR. Noticethat DR is elected, while BDR is not elected since there is no other candidate router present onthe LAN network. The debugoutput should resemble the following printout.

11:07:57: %LINEPROTO-5-UPDOWN: Line protocol on InterfaceFastEthernet0/0, changed state to up11:07:57: OSPF: Interface FastEthernet0/0 going Up11:08:03: OSPF: Rcv hello from 10.0.0.12 area 0 from FastEthernet0/0

10.1.2.211:08:03: OSPF: 2 Way Communication to 10.0.0.12 on FastEthernet0/0,state 2WAY11:08:03: OSPF: End of hello processing11:08:13: OSPF: Rcv hello from 10.0.0.12 area 0 from FastEthernet0/010.1.2.211:08:13: OSPF: End of hello processing11:08:23: OSPF: Rcv hello from 10.0.0.12 area 0 from FastEthernet0/010.1.2.211:08:23: OSPF: End of hello processing11:08:33: OSPF: Rcv hello from 10.0.0.12 area 0 from FastEthernet0/010.1.2.211:08:33: OSPF: Backup seen Event before WAIT timer on FastEthernet0/011:08:33: OSPF: DR/BDR election on FastEthernet0/011:08:33: OSPF: Elect BDR 0.0.0.011:08:33: OSPF: Elect DR 10.0.0.12

11:08:33: DR: 10.0.0.12 (Id) BDR: none11:08:33: OSPF: Send DBD to 10.0.0.12 on FastEthernet0/0 seq 0x1891 opt0x42 flag 0x7 len 3211:08:33: OSPF: End of hello processing


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11:08:33: OSPF: Rcv DBD from 10.0.0.12 on FastEthernet0/0 seq 0x1891 opt0x42 flag 0x2 len 132 mtu 1500 state EXSTART11:08:33: OSPF: NBR Negotiation Done. We are the MASTER11:08:33: OSPF: Send DBD to 10.0.0.12 on FastEthernet0/0 seq 0x1892 opt0x42 flag 0x3 len 13211:08:33: OSPF: Database request to 10.0.0.1211:08:33: OSPF: sent LS REQ packet to 10.1.2.2, length 2411:08:33: OSPF: Rcv DBD from 10.0.0.12 on FastEthernet0/0 seq 0x1892 opt0x42 flag 0x0 len 32 mtu 1500 state EXCHANGE

11:08:33: OSPF: Send DBD to 10.0.0.12R4(config-if)#on FastEthernet0/0 seq 0x1893 opt 0x42 flag 0x1 len 3211:08:33: OSPF: Rcv DBD from 10.0.0.12 on FastEthernet0/0 seq 0x1893 opt0x42 flag 0x0 len 32 mtu 1500 state EXCHANGE11:08:33: OSPF: Exchange Done with 10.0.0.12 on FastEthernet0/011:08:33: OSPF: Synchronized with 10.0.0.12 on FastEthernet0/0, stateFULL11:08:33: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.12 on FastEthernet0/0from LOADING to FULL, Loading Done

Printout 31: DR election process

Step 46 Verify the results of the election process by examining the OSPF interface information on R4router. Notice that no router was elected for the BDR role.

R4#show ip ospf interface FastEthernet 0/0FastEthernet0/0 is up, line protocol is upInternet Address 10.1.2.4 255.255.255.0, Area 0Process ID 1, Router ID 10.200.200.14, Network Type BROADCAST, Cost: 1Transmit Delay is 1 sec, State DROTHER, Priority 0Designated Router (ID) 10.0.0.12, Interface address 10.1.2.2No backup designated router on this networkTimer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:02

Index 1/1, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 1, maximum is 2Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 1, Adjacent neighbor count is 1Adjacent with neighbor 10.0.0.12 (Designated Router)Suppress hello for 0 neighbor(s)

R4#

Printout 32: OSPF information for Fe0/0 interface on R4router

Step 47 Disable the debugging of OSPF events onR4router and re-enable Fe0/0 and S0/0.1 interfaces.

Task 5: Configuring OSPF Cost

The connection betweenR1andR2routers should be used as a primary connection for the trafficbetween the two LANs. The connection betweenR3andR4routers for the traffic between the

LANs should only be used in case of a primary connection failure. To achieve that you willchange the OSPF cost to appropriate value.

Step 48 First check the cost and next-hop to reach 10.1.2.0/24 network onR3router. The network isreachable through S0/0.1 with the cost of 1563, where 1562 is the cost of serial connection to R4and 1 is the initial cost of the directly connected LAN network.

R3#show ip route 10.1.2.0 255.255.255.0Routing entry for 10.1.2.0 255.255.255.0Known via "ospf 1", distance 110, metric 1563, type intra areaLast update from 10.1.3.4 on Serial0/0.1, 00:04:56 agoRouting Descriptor Blocks:* 10.1.3.4, from 10.0.0.12, 00:04:56 ago, via Serial0/0.1

Route metric is 1563, traffic share count is 1

Printout 33: Routing information for 10.1.2.0 /24 network on R3


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Lab Topology

Routers in your lab are connected according to the setup in the following figure.

Figure 7: Lab Topology

The routers have different roles as detailed in the following table:

Router name Router role in the laboratoryR1, R2 Edge routers

R3, R4 Internal routers

Table 6: Roles of routers in topology

The routers are connected with Ethernet and Frame Relay links the first serial interface of eachrouter is connected to a Frame Relay switch, which is simulated by a router (not included in the

picture) that is pre-configured and is not accessible during the lab. The DLCI values forindividual sub-interface Frame Relay connections are given in the following table:

Source router DLCI IP address Destination router DLCI IP address

R1 723 10.1.0.1 R2 732 10.1.0.2

R3 714 10.1.3.3 R4 741 10.1.3.4

Table 7: Frame Relay DLCI values


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Addressing and Routing

This section contains information on IP addressing ranges used in the remote lab.

Note IP addressing, except loopback addresses, has been pre-configured to allow you to focus

exclusively on the objectives of the exercise.

IP Addressing Scheme

The addressing of lab exercise routers uses the following IP allocation scheme:

Parameter Value

R1 to R2 point-to-point connection subnet 10.1.0.0/24

R3 to R4 point-to-point connection subnet 10.1.3.0/24

LAN subnet between R1 and R3 10.1.1.0/24

LAN subnet between R2 and R4 10.1.2.0/24

R3 loopback interface 10.200.200.13/32

R4 loopback interface 10.200.200.14/32

Table 8: Network address space

The actual addresses used on WAN and LAN links configured on the Lab exercise routers aredisplayed in the following figure:

Figure 8: Addressing of Lab exercise routers

Note The addresses shown in a box overlaying the router are the loopback addresses configured on

the router. The address shown in a callout pointing to a router interface is the IP addressconfigured on that interface.


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Copyright2006, NIL Data Communications Configuring and Examining OSPF in a Single Area Lab Solutions 33

BSCI

Configuring and ExaminingOSPF in a Single Area

Lab Solutions

Lab Solution

Task 1: Configuring Single Area OSPF

The following commands need to be entered onR1, R2, R3 andR4 routers:

router ospf 1

network 10.1.0.0 0.0.255.255 area 0

Configuration 7: OSPF configuration on R1, R2, R3 and R4 routers

The following table lists the OSPF router IDs on R1,R2,R3andR4routers.

Router Router ID

R1 10.1.1.1

R2 10.1.2.2

R3 10.1.3.3

R4 10.1.3.4

Table 9: Router IDs

Task 2: Configuring Stable OSPF Router ID


router ospf 1

router-id 10.0.0.11

Configuration 8: OSPF router ID configuration onR1

router



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34 Configuring and Examining OSPF in a Single Area Lab Solutions Copyright2006, NIL Data Communications

router ospf 1

router-id 10.0.0.12

Configuration 9: OSPF router ID configuration on R2 router


interface Loopback0

ip address 10.200.200.13 255.255.255.255!no router ospf 1

!router ospf 1

network 10.1.0.0 0.0.255.255 area 0

Configuration 10: Loopback configuration on R3 router


interface Loopback0

ip address 10.200.200.14 255.255.255.255

!

no router ospf 1

!router ospf 1

network 10.1.0.0 0.0.255.255 area 0

Configuration 11: Loopback configuration on R4 router

Task 4: Understanding OSPF DR and BDR Elections


interface FastEthernet0/0

ip ospf priority 0

Configuration 12: OSPF priority adjustment on R4 router

Task 5: Configuring OSPF Cost



ip ospf cost 2000

Configuration 13: OSPF link cost adjustment on R3 and R4 routers

Answers to Review Questions

Q1: What is the default administrative distance for OSPF?

A1: The default OSPF administrative distance is 110.

Q2: What is the OSPF metric based on?

A2: OSPF uses cost for metric. By default, cost is calculated as the inverse value of bandwidth inbits per second, multiplied by 10

8.

Q3: What kind of load balancing does OSPF support?


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Copyright2006, NIL Data Communications Configuring and Examining OSPF in a Single Area Lab Solutions 35

A3: OSPF supports only equal-cost load balancing.

Q4: What is the default OSPF router priority used in DR/BDR election?

A4: Default OSPF router priority is 1.


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36 Configuring and Examining OSPF in a Single Area Lab Solutions Copyright2006, NIL Data Communications


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Copyright2006, NIL Data Communications Configuring OSPF for Frame Relay Environment 37

BSCI

Configuring OSPF for FrameRelay Environment

Objective

In this exercise, you will configure a multi-area OSPF network and focus on an OSPF operationin a Frame Relay environment. You will configure different OSPF Non-Broadcast MultipleAccess (NBMA) types of operation through the lab exercise and inspect OSPF behavior withinthe network.


Configure and examine OSPF non-backbone area over Frame Relay point-to-point and

Ethernet interfaces.

Configure and examine OSPF backbone area over Frame Relay using the NBMA OSPFnetwork type.

Configure and examine OSPF backbone area over Frame Relay using the point-to-multipointOSPF network type.

The following figure shows the logical topology used for this lab.


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38 Configuring OSPF for Frame Relay Environment Copyright2006, NIL Data Communications

Figure 9: Configuring OSPF for Frame Relay Environment Lab exercise logicaltopology




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Command List

Use the following commands to complete this exercise:

Command Task

ip ospf network {broadcast | non-broadcast| {point-to-multipoint [non-broadcast]}}

Configures the OSPF network type to a typeother than the default for a given media.

ip ospf priority value Changes the OSPF router priority to value.

neighbor ip-address Configures OSPF routers interconnecting tonon-broadcast networks

network ip-addresswildcardarea area-number

Specifies the interfaces on which to runOSPF, and their areas.

ping destination Performs ping to a destination address.

router ospfprocess-ID Enables OSPF with a process ID ofprocess-ID.

show ip ospf adatabase Displays the content of OSPF database.show ip ospf interface Displays OSPF-specific information about an

interface.

show ip ospf neighbor Displays information about OSPF neighbors.

show ip route Displays the IP routing table.

traceroute destination Performs traceroute to a destination address.

Table 10: Configuration and monitoring commands used in the ConfiguringOSPF for Frame Relay Environment Lab exercise


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Task 1: Configuring Non-Backbone OSPF Area

Step 1 Start the OSPF with the process ID 1 atR3 andR4 routers and place all active interfaces in theOSPF area 1.

Step 2 Start the OSPF with the process ID 1 atR1 andR2 routers also and place only S0/0.1 and Fe0/0interfaces in the OSPF area 1.


all printouts in the lab were taken on routers with Ethernet interfaces, the default bandwidth

and the default delay on Ethernet interfaces were changed to FastEthernet interface default

values for compatibility reasons.

Verification

Step 3 Begin the verification by checking that you have full connectivity within the OSPF area 1 usingthe pingcommand. Make sure that you can pingall interfaces within OSPF area 1.

Step 4 Examine the OSPF interface information atR3 router with the show ip ospf interface commandfor interfaces S0/0.1 and Fe0/0. Focus on network type, hello and dead interval fields. Thedefault OSPF network type for any point-to-point interface including Frame Relay point-to-pointsubinterfaces is point-to-point. On broadcast media the default OSPF network type is broadcast.

R3#show ip ospf interfaceLoopback0 is up, line protocol is upInternet Address 10.200.200.13 255.255.255.255, Area 1Process ID 1, Router ID 10.200.200.13, Network Type LOOPBACK, Cost: 1Loopback interface is treated as a stub Host

Serial0/0.1 is up, line protocol is upInternet Address 10.1.3.3 255.255.255.0, Area 1Process ID 1, Router ID 10.200.200.13, Network Type POINT_TO_POINT,

Cost: 64Transmit Delay is 1 sec, State POINT_TO_POINT,Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:07

Index 2/2, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 1, maximum is 2Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 10.200.200.14Suppress hello for 0 neighbor(s)

Ethernet0/0 is up, line protocol is upInternet Address 10.1.1.3 255.255.255.0, Area 1Process ID 1, Router ID 10.200.200.13, Network Type BROADCAST, Cost: 1Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 10.200.200.13, Interface address 10.1.1.3Backup Designated router (ID) 10.200.200.11, Interface address 10.1.1.1Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 00:00:05

Index 1/1, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 2, maximum is 2Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 10.200.200.11 (Backup Designated Router)Suppress hello for 0 neighbor(s)

Printout 38: OSPF interface information on R3router


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Step 5 Take a look at the OSPF neighbor relationships atR3 router. The OSPF operation over OSPFpoint-to-point network type does not require DR and BDR routers as with broadcast networktype.


Neighbor ID Pri State Dead Time AddressInterface10.200.200.14 1 FULL/ - 00:00:36 10.1.3.4Serial0/0.110.200.200.11 1 FULL/BDR 00:00:30 10.1.1.1Ethernet0/0

Printout 39: OSPF neighbors on R3 router

Step 6 Examine routing tables ofR1,R2,R3 andR4 routers.You should see that routing table ispopulated with the OSPF learned routes as in the exemplary output fromR3 router shown below.

R3#show ip route...


10.0.0.0 255.0.0.0 is variably subnetted, 6 subnets, 2 masks

O 10.200.200.14 255.255.255.255[110/65] via 10.1.3.4, 00:04:25, Serial0/0.1

C 10.200.200.13 255.255.255.255 is directly connected, Loopback0C 10.1.3.0 255.255.255.0 is directly connected, Serial0/0.1O 10.1.2.0 255.255.255.0 [110/65] via 10.1.3.4, 00:04:25,Serial0/0.1C 10.1.1.0 255.255.255.0 is directly connected, Ethernet0/0O 10.1.0.0 255.255.255.0 [110/65] via 10.1.1.1, 00:04:25,Ethernet0/0

Printout 40: Routing table on R3 router

Task 2: Using NBMA OSPF Network Type over Frame RelayStep 7 Enable OSPF with the process ID 1 atBBR1 core router and place all interfaces in the OSPF area

0.

Step 8 Place the S0/0.2 and Loopback0 interfaces in the OSPF area 0 atR1 andR2 routers.

Verification

Step 9 Check the S0/0.2 OSPF interface information atR1,R2 andBBR1 routers with the show ip ospfinterfacecommand.

Note After enabling OSPF on BBR1 interfaces, wait for two minutes before issuing the show ip

ospf interfacecommand on the BBR. This is the value of the Waittimer used for DR/BDR

election on an OSPF interface. After Waittimer expiration, the router proclaims itself as the

DR over that interface.

Pay special attention to network type, hello and dead interval, state and priority. The routers areconnected via Frame Relay point-to-multipoint subinterfaces with the OSPF NMBA networktype, which is a default for such interfaces. Notice that OSPF interface state on all three routers isindicating that each router is DR on that segment, but no OSPF adjacency was formed throughthe interface.

BBR1#show ip ospf interface serial 0/0.2Serial0/0.2 is up, line protocol is upInternet Address 172.31.1.3 255.255.255.0, Area 0


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Process ID 1, Router ID 172.31.1.3, Network Type NON_BROADCAST, Cost:1562Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 172.31.1.3, Interface address 172.31.1.3No backup designated router on this networkTimer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5Hello due in 00:00:18

Index 2/2, flood queue length 0Next 0x0(0)/0x0(0)

Last flood scan length is 0, maximum is 0Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 0, Adjacent neighbor count is 0Suppress hello for 0 neighbor(s)

Printout 41: S0/0.2 interface OSPF information on BBR1 router

Step 10 Now examine the OSPF neighbor table atBBR1 router. The router has established the adjacencyonly withBBR3 router. You wont see OSPF adjacencies formed withR1 orR2 routers becausethe OSPF neighbors are not discovered over interfaces with OSPF NMBA network type.

BBR1#show ip ospf neighbor

Neighbor ID Pri State Dead Time AddressInterface

10.254.0.3 1 FULL/ - 00:00:33 10.254.0.3Serial0/0.1

Printout 42: OSPF neighbor table on BBR1router

Step 11 The OSPF database atBBR1 router is almost empty at the moment except for a two Type-1LSAs also known as Router LSAs. Type-1 LSAs describe the routers BBR1 andBBR3in area 0and the state of their connected links. Check the OSPF database content with show ip ospfdatabase command.

BBR1#show ip ospf database

OSPF Router with ID (172.31.1.3) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Linkcount10.254.0.3 10.254.0.3 535 0x80000004 0x574D 2172.31.1.3 172.31.1.3 530 0x80000003 0x20C6 3

Printout 43: OSPF database on BBR1 router

Step 12 The consequence of an almost empty OSPF database onBBR1 is the routing table with no OSPFlearned routes. This can be verified with the show ip route command.

BBR1#show ip route...


172.31.0.0 255.255.255.0 is subnetted, 1 subnetsC 172.31.1.0 is directly connected, Serial0/0.2




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Task 3: Configuring OSPF Neighbor relationship and DRRouter for NBMA Network Type

The OSPF NBMA network type (called Non-broadcast in Cisco IOS) requires the manualconfiguration of neighbors as well as election of DR and BDR routers. If a Frame Relay networkis fully meshed, the neighbors can be configured on all routers or at least on DR and BDR

routers. In a hub and spoke topology only a hub router has a full connectivity to the spokerouters. As a consequence only a hub router can play the DR role and it is enough to configureneighbors on hub router only.

Step 13 Set the OSPF priority on S0/0.2 interfaces to 0 at R1 andR2 routers. The priority value of 0prevents the routers from starting the election process for the DR and BDR role.

Step 14 ConfigureR1 andR2 as OSPF neighbors atBBR1 router.

Verification

Step 15 The first verification step is checking the status of S0/0.2 OSPF interface at R1,R2 andBBR1routers with show ip ospf interfacecommand. Because of the priority set atR1 andR2 routers,theBBR1became the DR. The printouts show the OSPF interface information for interfacesS0/0.2 on routersBBR1, R1 andR2.

BBR1#show ip ospf interface serial 0/0.2Serial0/0.2 is up, line protocol is upInternet Address 172.31.1.3 255.255.255.0, Area 0Process ID 1, Router ID 172.31.1.3, Network Type NON_BROADCAST, Cost:

1562Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 172.31.1.3, Interface address 172.31.1.3No backup designated router on this networkTimer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

Hello due in 00:00:08Index 2/2, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 1, maximum is 7Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 2, Adjacent neighbor count is 2Adjacent with neighbor 10.200.200.12Adjacent with neighbor 10.200.200.11Suppress hello for 0 neighbor(s)

Printout 45: S0/0.2 interface OSPF information on BBR1 router

R1#show ip ospf interface serial 0/0.2Serial0/0.2 is up, line protocol is upInternet Address 172.31.1.1 255.255.255.0, Area 0

Process ID 1, Router ID 10.200.200.11, Network Type NON_BROADCAST,Cost: 64Transmit Delay is 1 sec, State DROTHER, Priority 0Designated Router (ID) 172.31.1.3, Interface address 172.31.1.3No backup designated router on this networkFlush timer for old DR LSA due in 00:00:54Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5Hello due in 00:00:23


Printout 46: S0/0.2 interface OSPF information on R1 router


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R2#show ip ospf interface serial 0/0.2Serial0/0.2 is up, line protocol is upInternet Address 172.31.1.2 255.255.255.0, Area 0Process ID 1, Router ID 10.200.200.12, Network Type NON_BROADCAST,

Cost: 64Transmit Delay is 1 sec, State DROTHER, Priority 0Designated Router (ID) 172.31.1.3, Interface address 172.31.1.3No backup designated router on this networkFlush timer for old DR LSA due in 00:00:33

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5Hello due in 00:00:21


Printout 47: S0/0.2 interface OSPF information on R2 router

Step 16 Verify the state of OSPF adjacencies with show ip ospf neighborcommand. TheBBR1 routerhas now formed the OSPF adjacency withR1 andR2 routers.


Neighbor ID Pri State Dead Time AddressInterface10.200.200.12 0 FULL/DROTHER 00:01:37 172.31.1.2Serial0/0.210.200.200.11 0 FULL/DROTHER 00:01:55 172.31.1.1Serial0/0.210.254.0.3 1 FULL/ - 00:00:31 10.254.0.3Serial0/0.1

Printout 48: OSPF neighbors on BBR1 router


Neighbor ID Pri State Dead Time AddressInterface172.31.1.3 1 FULL/DR 00:01:45 172.31.1.3Serial0/0.210.200.200.12 1 FULL/ - 00:00:35 10.1.0.2Serial0/0.110.200.200.13 1 FULL/DR 00:00:34 10.1.1.3Ethernet0/0



Neighbor ID Pri State Dead Time AddressInterface172.31.1.3 1 FULL/DR 00:01:38 172.31.1.3

Serial0/0.210.200.200.11 1 FULL/ - 00:00:38 10.1.0.1Serial0/0.110.200.200.14 1 FULL/BDR 00:00:34 10.1.2.4Ethernet0/0


Step 17 The OSPF database now contains a lot more information than before: Four Type-1 LSAsdescribingR1,R2,BBR1andBBR3routers, one Type-2 LSA generated by the DR routerdescribing the multi-access Frame Relay network with attached routers, and several Type-3LSAs generated by the ABR routersR1 andR2, describing the networks from the area 1.Checkthe OSPF database content with show ip ospf database command.


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Link ID ADV Router Age Seq# Checksum Linkcount10.200.200.11 10.200.200.11 35 0x80000003 0xBC91 2

10.200.200.12 10.200.200.12 23 0x80000003 0xD079 210.254.0.3 10.254.0.3 1265 0x80000004 0x574D 2172.31.1.3 172.31.1.3 576 0x80000004 0x45CE 3

Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum172.31.1.3 172.31.1.3 576 0x80000001 0xEA8D

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum10.1.0.0 10.200.200.11 1252 0x80000001 0x1D2E10.1.0.0 10.200.200.12 1240 0x80000001 0x173310.1.1.0 10.200.200.11 1252 0x80000001 0x99EF

10.1.1.0 10.200.200.12 1240 0x80000001 0x163210.1.2.0 10.200.200.11 1252 0x80000001 0x113710.1.2.0 10.200.200.12 1242 0x80000001 0x88FE10.1.3.0 10.200.200.11 1253 0x80000001 0x64110.1.3.0 10.200.200.12 1242 0x80000001 0xFF4610.200.200.13 10.200.200.11 1253 0x80000001 0x2EBD10.200.200.13 10.200.200.12 1242 0x80000001 0xAAFF10.200.200.14 10.200.200.11 1253 0x80000001 0xA60410.200.200.14 10.200.200.12 1242 0x80000001 0x1ECB

Printout 51: OSPF database on BBR1 router

Step 18 The routing table onBBR1 router is now populated with OSPF learned routes. The output shouldbe similar to the following printout.

BBR1#show ip route...



10.0.0.0 255.0.0.0 is variably subnetted, 9 subnets, 2 masksO 10.200.200.11 255.255.255.255

[110/1563] via 172.31.1.1, 00:00:54, Serial0/0.2O IA 10.200.200.14 255.255.255.255

[110/1564] via 172.31.1.2, 00:00:54, Serial0/0.2O 10.200.200.12 255.255.255.255

[110/1563] via 172.31.1.2, 00:00:54, Serial0/0.2O IA 10.200.200.13 255.255.255.255

[110/1564] via 172.31.1.1, 00:00:56, Serial0/0.2

O IA 10.1.3.0 255.255.255.0[110/1627] via 172.31.1.1, 00:00:56, Serial0/0.2[110/1627] via 172.31.1.2, 00:00:56, Serial0/0.2

O IA 10.1.2.0 255.255.255.0[110/1563] via 172.31.1.2, 00:00:56, Serial0/0.2

O IA 10.1.1.0 255.255.255.0[110/1563] via 172.31.1.1, 00:00:56, Serial0/0.2

O IA 10.1.0.0 255.255.255.0[110/1626] via 172.31.1.1, 00:00:56, Serial0/0.2[110/1626] via 172.31.1.2, 00:00:56, Serial0/0.2

C 10.254.0.0 255.255.255.0 is directly connected, Serial0/0.1



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Step 19 It looks like the OSPF NMBA network type is working for the hub and spoke topology. But thepingsfromR1 to loopback onR2 and fromR2 to loopback onR1 do not succeed.

R1#ping 10.200.200.12

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.200.200.12, timeout is 2 seconds:.....

Success rate is 0 percent (0/5)

Printout 53: Ping from R1 router to R2 routers loopback interface.

R2#ping 10.200.200.11

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.200.200.11, timeout is 2 seconds:.....

Success rate is 0 percent (0/5)

Printout 54: Ping from R2 router to R1 routers loopback interface.

Step 20 Checking the routing table with the show ip route command onR1 andR2 routers reveals thereason. The routing table contains the route to the remote loopback with the next hop set to the

S0/0.2 interfaces IP address of the remote router. But that next-hop is not accessible since R1cannot reachR2 over S0/0.2 interface and vice versa. This is becauseR1has no frame-relaymapping for the IP address of this next-hop, therefore layer 2 encapsulation will fail. Theconclusion is that a full mesh is required, in other words, direct connectivity between R1 andR2routers should be available, because the loopback network appears to be one hop away.

R1#show ip route...



10.0.0.0 255.0.0.0 is variably subnetted, 9 subnets, 2 masksC 10.200.200.11 255.255.255.255 is directly connected, Loopback0

O 10.200.200.14 255.255.255.255[110/66] via 10.1.1.3, 00:25:04, Ethernet0/0[110/66] via 10.1.0.2, 00:25:04, Serial0/0.1

O 10.200.200.12 255.255.255.255[110/65] via 172.31.1.2, 00:04:52, Serial0/0.2

O 10.200.200.13 255.255.255.255[110/2] via 10.1.1.3, 00:25:05, Ethernet0/0

O 10.1.3.0 255.255.255.0 [110/65] via 10.1.1.3, 00:25:05,Ethernet0/0O 10.1.2.0 255.255.255.0 [110/65] via 10.1.0.2, 00:25:05,Serial0/0.1C 10.1.1.0 255.255.255.0 is directly connected, Ethernet0/0C 10.1.0.0 255.255.255.0 is directly connected, Serial0/0.1O 10.254.0.0 255.255.255.0

[110/128] via 172.31.1.3, 00:04:54, Serial0/0.2

Printout 55: IP routing table output onR1

router

R2#show ip route...



10.0.0.0 255.0.0.0 is variably subnetted, 9 subnets, 2 masksO 10.200.200.11 255.255.255.255

[110/65] via 172.31.1.1, 00:06:49, Serial0/0.2O 10.200.200.14 255.255.255.255

[110/2] via 10.1.2.4, 00:27:01, Ethernet0/0C 10.200.200.12 255.255.255.255 is directly connected, Loopback0

O 10.200.200.13 255.255.255.255[110/66] via 10.1.2.4, 00:27:02, Ethernet0/0[110/66] via 10.1.0.1, 00:27:02, Serial0/0.1


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O 10.1.3.0 255.255.255.0 [110/65] via 10.1.2.4, 00:27:02,Ethernet0/0C 10.1.2.0 255.255.255.0 is directly connected, Ethernet0/0O 10.1.1.0 255.255.255.0 [110/65] via 10.1.0.1, 00:27:02,Serial0/0.1C 10.1.0.0 255.255.255.0 is directly connected, Serial0/0.1O 10.254.0.0 255.255.255.0

[110/128] via 172.31.1.3, 00:06:50, Serial0/0.2

Printout 56: IP routing table output on R2 router

Task 4: Using Point-to-Multipoint OSPF Network Type overFrame Relay

You have seen that the OSPF NBMA network type is not suitable for a partially meshedtopology. You will now use the OSPF point-to-multipoint representation.

Step 21 First, remove the manually configured OSPF neighbors atBBR1 router.

Step 22 Configure OSPF point-to-multipoint network type on S0/0.2 interfaces atR1,R2andBBR1routers.

Verification

Step 23 Start verification by inspecting the OSPF adjacencies onR1,R2andBBR1 routers using theshow ip ospf neighborcommand. The OSPF point-to-multipoint mode operates similar to OSPF

point-to-point mode. The DR and BDR routers are not required and the adjacencies areestablished between the neighbors.


Neighbor ID Pri State Dead Time AddressInterface10.200.200.11 0 FULL/ - 00:01:44 172.31.1.1Serial0/0.210.200.200.12 0 FULL/ - 00:01:52 172.31.1.2Serial0/0.210.254.0.3 1 FULL/ - 00:00:33 10.254.0.3Serial0/0.1



Neighbor ID Pri State Dead Time AddressInterface172.31.1.3 1 FULL/ - 00:01:58 172.31.1.3Serial0/0.210.200.200.12 1 FULL/ - 00:00:37 10.1.0.2Serial0/0.110.200.200.13 1 FULL/DR 00:00:35 10.1.1.3Ethernet0/0



Neighbor ID Pri State Dead Time AddressInterface172.31.1.3 1 FULL/ - 00:01:56 172.31.1.3Serial0/0.210.200.200.11 1 FULL/ - 00:00:34 10.1.0.1

Serial0/0.110.200.200.14 1 FULL/BDR 00:00:30 10.1.2.4Ethernet0/0



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Step 24 Now check the status of S0/0.2 OSPF interface onBBR1 router with show ip ospf interface. TheOSPF network type should be set to point-to-multipoint.

BBR1#show ip ospf interface serial 0/0.2Serial0/0.2 is up, line protocol is upInternet Address 172.31.1.3 255.255.255.0, Area 0Process ID 1, Router ID 172.31.1.3, Network Type POINT_TO_MULTIPOINT,

Cost: 1562Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT,

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5Hello due in 00:00:24

Index 2/2, flood queue length 0Next 0x0(0)/0x0(0)Last flood scan length is 6, maximum is 7Last flood scan time is 0 msec, maximum is 0 msecNeighbor Count is 2, Adjacent neighbor count is 2Adjacent with neighbor 10.200.200.11Adjacent with neighbor 10.200.200.12Suppress hello for 0 neighbor(s)


Step 25 The OSPF database for Area0 does not contain the Type-2 LSA describing the multi-accessFrame Relay network with attached routers any more since OSPF treats the network as acollection of point-to-point links. Check the OSPF database content with show ip ospf databasecommand.




Link ID ADV Router Age Seq# Checksum Linkcount10.200.200.11 10.200.200.11 611 0x80000005 0x56A 310.200.200.12 10.200.200.12 612 0x80000005 0x3B2F 310.254.0.3 10.254.0.3 436 0x80000005 0x554E 2172.31.1.3 172.31.1.3 611 0x8000000A 0x575B 5

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum10.1.0.0 10.200.200.11 548 0x80000002 0x1B2F10.1.0.0 10.200.200.12 417 0x80000002 0x153410.1.1.0 10.200.200.11 548 0x80000002 0x97F010.1.1.0 10.200.200.12 417 0x80000002 0x143310.1.2.0 10.200.200.11 548 0x80000002 0xF3810.1.2.0 10.200.200.12 417 0x80000002 0x86FF10.1.3.0 10.200.200.11 548 0x80000002 0x44210.1.3.0 10.200.200.12 419 0x80000002 0xFD4710.200.200.13 10.200.200.11 549 0x80000002 0x2CBE10.200.200.13 10.200.200.12 419 0x80000002 0xA80110.200.200.14 10.200.200.11 550 0x80000002 0xA405

10.200.200.14 10.200.200.12 419 0x80000002 0x1CCCPrintout 61: OSPF database on BBR1 router

Step 26 As a result, the routing table now contains host routes for each OSPF neighbor on the172.31.1.0/24 network. TheR1 andR2can now reach each others loopback interfaces since thenext hop

BSCI30_NIL_Lab_Guide.pdf

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