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.
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
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.
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
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.
