Video:Simple BGP troubleshooting

From CT3

The video describes simple BGP troubleshooting techniques, including session troubleshooting, BGP route origination troubleshooting and route propagation troubleshooting. These procedures are illustrated in a simple two-site MPLS/VPN-based network using BGP as the PE-CE routing protocol.


Command	Explanation
show ip protocol	Display the routing protocols running on a router
show ip bgp summary	Display the state of BGP sessions
show ip route prefix	Display a single IP prefix in the IP routing table
show ip bgp	Display the contents of the BGP table
show ip bgp prefix	Display a single IP prefix in the BGP table
show ip bgp regexp	Display BGP routes where the AS-path matches the specified regular expression
show ip bgp neighbor advertised	Display BGP routes advertised to the specified neighbor

BGP troubleshooting video

Router configurations

Configuration of CE-A

hostname Site-A
!
interface Loopback0
 ip address 10.0.1.5 255.255.255.255
!
interface FastEthernet0/0
 description Site A LAN
 ip address 10.2.3.1 255.255.255.0
!
interface Serial1/0
 description Link to PE router
 ip address 192.168.1.6 255.255.255.252
 encapsulation ppp
!
router bgp 65101
 bgp log-neighbor-changes
 neighbor 192.168.1.5 remote-as 65000
 redistribute connected
 no auto-summary

Configuration of CE-B

hostname Site-B
!
interface Loopback0
 ip address 10.0.1.6 255.255.255.255
!
interface FastEthernet0/0
 description Site-B LAN
 ip address 10.2.1.1 255.255.255.0
!
interface Serial1/0
 description Link to PE router
 ip address 192.168.1.18 255.255.255.252
 encapsulation ppp
!
router bgp 65102
 bgp log-neighbor-changes
 redistribute connected
 neighbor 192.168.1.17 remote-as 65000
 no auto-summary