Lab 140 - BGP Fast Fallover

Lab 140 - BGP Fast Fallover
Di Posting Oleh : Simple Learning
Kategori : BGP Core Technologies Routing

Prerequisites: CCNP level skills.

Topology

Pic. 1 - Topology Diagram.

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

Task 1
Configure full mesh BGP peering according to the topology diagram (pic. 1). Make sure that all BGP sessions in AS 100 can survive a single link loss. If IGP protocol must used, OSPF should be configured. Advertise Loopbacks into BGP.

Task 2
Configure R3 in such a way so the response time of BGP to adjacency changes is improved. Use a method of detecting the loss of the peer that is not based on the interface state but is event driven such as a loss of the path to the IGP address used for peering.

Solution

Task 1

Configure full mesh BGP peering according to the topology diagram (pic. 1). Make sure that all BGP sessions in AS 100 can survive a single link loss. If IGP protocol must be used, OSPF should be configured. Advertise Loopbacks into BGP.

R1 Configuration:

!

router ospf 1
 router-id 172.16.101.1
 log-adjacency-changes
 network 10.1.13.1 0.0.0.0 area 0
 network 10.1.14.1 0.0.0.0 area 0
 network 172.16.101.1 0.0.0.0 area 0

!

router bgp 100
 no synchronization
 bgp router-id 172.16.101.1
 bgp log-neighbor-changes

 network 172.16.101.0 mask 255.255.255.0
 neighbor 172.16.102.2 remote-as 100
 neighbor 172.16.102.2 update-source Loopback0
 neighbor 172.16.103.3 remote-as 100
 neighbor 172.16.103.3 update-source Loopback0
 neighbor 172.16.104.4 remote-as 100
 neighbor 172.16.104.4 update-source Loopback0
 no auto-summary

!

R2 Configuration:

!

router ospf 1
 router-id 172.16.102.2
 log-adjacency-changes
 network 10.1.23.2 0.0.0.0 area 0
 network 10.1.24.2 0.0.0.0 area 0
 network 172.16.102.2 0.0.0.0 area 0

!

router bgp 100
 no synchronization
 bgp router-id 172.16.102.2
 bgp log-neighbor-changes

 network 172.16.102.0 mask 255.255.255.0
 neighbor 172.16.101.1 remote-as 100
 neighbor 172.16.101.1 update-source Loopback0
 neighbor 172.16.103.3 remote-as 100
 neighbor 172.16.103.3 update-source Loopback0
 neighbor 172.16.104.4 remote-as 100
 neighbor 172.16.104.4 update-source Loopback0
 no auto-summary

!

R3 Configuration:

!

router ospf 1
 router-id 172.16.103.3
 log-adjacency-changes
 network 10.1.13.3 0.0.0.0 area 0
 network 10.1.23.3 0.0.0.0 area 0
 network 172.16.103.3 0.0.0.0 area 0

! 

router bgp 100
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes

 network 172.16.103.0 mask 255.255.255.0
 neighbor 10.1.35.5 remote-as 50
 neighbor 172.16.101.1 remote-as 100
 neighbor 172.16.101.1 update-source Loopback0
 neighbor 172.16.102.2 remote-as 100
 neighbor 172.16.102.2 update-source Loopback0
 neighbor 172.16.104.4 remote-as 100
 neighbor 172.16.104.4 update-source Loopback0
 no auto-summary

!

R4 Configuration:

!

router ospf 1
 router-id 172.16.104.4
 log-adjacency-changes
 network 10.1.14.4 0.0.0.0 area 0
 network 10.1.24.4 0.0.0.0 area 0
 network 172.16.104.4 0.0.0.0 area 0

!

router bgp 100
 no synchronization
 bgp router-id 172.16.104.4
 bgp log-neighbor-changes

 network 172.16.104.0 mask 255.255.255.0
 neighbor 172.16.101.1 remote-as 100
 neighbor 172.16.101.1 update-source Loopback0
 neighbor 172.16.102.2 remote-as 100
 neighbor 172.16.102.2 update-source Loopback0
 neighbor 172.16.103.3 remote-as 100
 neighbor 172.16.103.3 update-source Loopback0

!

Verification:

Pic. 2 - R1's BGP Neighbors.

Pic. 3 - R2's BGP Neighbors.

Pic. 4 - R3's BGP Neighbors.

Pic. 5 - R4's BGP Neighbors.

Task 2
Configure R3 in such a way so the response time of BGP to adjacency changes is improved. Use a method of detecting the loss of the peer that is not based on the interface state but is event driven such as a loss of the path to the IGP address used for peering.

R3 Configuration:

! 

router bgp 100
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes
 network 172.16.103.0 mask 255.255.255.0
 neighbor 10.1.35.5 remote-as 50
 neighbor 172.16.101.1 remote-as 100
 neighbor 172.16.101.1 update-source Loopback0
 neighbor 172.16.101.1 fall-over
 neighbor 172.16.102.2 remote-as 100
 neighbor 172.16.102.2 update-source Loopback0
 neighbor 172.16.102.2 fall-over
 neighbor 172.16.104.4 remote-as 100
 neighbor 172.16.104.4 update-source Loopback0
 neighbor 172.16.104.4 fall-over
 no auto-summary

!

Verification:

Pic. 6 - BGP Fallover. 

Source:
http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/cs_bsfda.html

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