Troubleshooting guide

Troubleshooting

Show IP BGP Neighbors

Use the show ip bgp neighbors command to display information for the specified BGP neighbor.

#show ip bgp neighbors [<ipv4 address>] [advertised-routes | received-routes | routes]

<ipv4 address> Optional. Displays information for the specified neighbor. IPv4 addresses should be

expressed in dotted decimal notation (for example, 10.10.10.1). If no IPv4 address is entered, information

for all neighbors is displayed.

advertised-routes Optional. Displays all routes being advertised to the specified neighbor. Command

output is the same as for show ip bgp except filtered to only the BGP routes being advertised to the

specified neighbor.

received-routes Optional. Displays all routes (accepted and rejected) advertised by the specified neighbor.

Routes can be rejected by inbound filters, such as prefix list filters.

routes Optional. Displays all accepted received routes advertised by the specified neighbor. Routes

displayed have passed inbound filtering. This command output is the same as show ip bgp except the

output is filtered to those learned from the specified neighbor.

The following examples show a couple of output variations of the show ip bgp neighbors command:

#show ip bgp neighbors

BGP neighbor is 10.15.43.17, remote AS 100, external link

Configured hold time is 180, keepalive interval is 60 seconds

Default minimum time between advertisement runs is 30 seconds

Connections established 6; dropped 5

Last reset: Interface went down

Connection ID: 15

BGP version 4, remote router ID 8.1.1.1

BGP state is Established, for 01:55:05

Negotiated hold time is 180, keepalive interval is 60 seconds

Message statistics:

InQ depth is 0, OutQ depth is 0

Local host: 10.15.43.18, Local port: 179

Sent Rcvd

Opens:1 1

Notifications: 0 0

Updates: 0 8

Keepalives: 116 116

Unknown: 0 0

Total: 117 125

Foreign host: 10.15.43.17, foreign port: 1048

Flags: passive open

Entries that are not filtered by a local BGP policy are marked with an asterisk (*) to show

they are valid. Entries that are deemed the best path to an advertised route are marked with

a caret (>).