Lab 83 - BGP Synchronization

Lab 83 - BGP Synchronization
Di Posting Oleh : Simple Learning
Kategori : BGP Core Technologies Routing

Prerequisites: CCNP level skills.

Topology

Note!

Use Lab 82 configuration to complete this lab.

Pic. 1 - Topology Diagram.

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

Task 1
Enable BGP Synchronization on R1. Ensure R1 can reach 172.16.105.0/24.

Lab Solution

Task 1

Enable BGP Synchronization on R1. Ensure R1 can reach 172.16.105.0/24.

Notice!

Synchronization is disabled by default in Cisco IOS Software Release 12.2(8)T and later.

BGP synchronization explained at:

http://docwiki.cisco.com/wiki/Internetworking_Case_Studies_--_Using_the_Border_Gateway_Protocol_for_Interdomain_Routing#Synchronization
  
R1 Configuration:

!

router bgp 13
 synchronization
 bgp router-id 1.1.1.1
 bgp log-neighbor-changes
 network 172.16.101.0 mask 255.255.255.0
 neighbor 172.16.103.3 remote-as 13
 neighbor 172.16.103.3 update-source Loopback0
 no auto-summary

!

Verification:

Pic. 2 - BGP Table on R1.

Notice!
The code for the best path '>' has been removed since the prefix is not synchronized with with IGP (IBGP loop prevention mechanism). It takes about a minute to see the change in the BGP table. The result: no reachability to 172.16.105.0/24 (prefix will not be installed in the routing table).

Pic. 3 - Prefix Details.

R3 Configuration:

!

ip prefix-list BGP_PREFIX seq 5 permit 172.16.105.0/24

!

route-map BGP_TO_OSPF permit 10
 match ip address prefix-list BGP_PREFIX
!
router ospf 1
 router-id 3.3.3.3
 log-adjacency-changes
 redistribute bgp 13 subnets route-map BGP_TO_OSPF
 network 10.1.13.3 0.0.0.0 area 0
 network 172.16.103.3 0.0.0.0 area 0

!

Verification:

Pic. 4 - R1's OSPF Routing Table.

Pic. 5 - R1's BGP Details

Pic. 6 - Reachability's Restored.

Tweet