Lab 121 - BGP Conditional Route Advertisement

Lab 121 - BGP Conditional Route Advertisement
Di Posting Oleh : Simple Learning
Kategori : BGP Core Technologies Routing

Prerequisites: CCNP level skills.

Note!
Topology from Lab 118.

Topology

Pic. 1 - Topology Diagram.

Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1
Configure R3 so that it advertises the default route only to R1. This default route should be advertised only if the interface between R3 and R5 is up.

Solution

Task 1

Configure R3 so that it advertises the default route only to R1. This default route should be advertised only if the interface between R3 and R5 is up.

Pic. 2 - R3 Has no Default Route Before Applying Configuration.

R3 Configuration:

!

ip prefix-list R3_R5_LINK seq 5 permit 10.1.35.0/24

!

route-map DEFAULT_ROUTE permit 10
 match ip address prefix-list R3_R5_LINK
!
router bgp 30
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes
 network 172.16.103.0 mask 255.255.255.0
 neighbor 10.1.13.1 remote-as 10
 neighbor 10.1.13.1 default-originate route-map DEFAULT_ROUTE
 neighbor 10.1.23.2 remote-as 20
 neighbor 10.1.35.5 remote-as 50
 no auto-summary

!

Verification:

Pic. 3 - R1's BGP Table.

 Pic. 4 - R2's BGP Table.

Notice!
Only R1 receives the default route.

Now, shutting down the E0/0 on R3. 

Pic. 5 - Link between R3 and R5 is Down.

Pic. 6 - R1 Loses the Default Route.

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