Troubleshooting guide

Troubleshooting

Debug Commands

Debug IP BGP

Use the debug ip bgp command to activate debug messages associated with BGP. Debug messages are

displayed in real time. Use the no form of this command to disable the debug messages.

events Optional. Displays significant BGP events, such as a neighbor state change.

in/out Optional. Displays the same information as the debug ip bgp command, but limits messages to the

specified direction (in or out).

keepalives Optional. Displays BGP keepalive packets.

updates Optional. Displays detailed information on BGP updates for all neighbors.

updates quiet Optional. Displays summary information about BGP neighbor updates. (Note: updates

quiet displays a one-line summary of the output that is displayed when debug ip bgp updates is issued.)

The following example enables debug messages on general outbound BGP messages and events:

#debug ip bgp out

#07:42:39: BGP OUT 10.15.240.1[2]: Transmitting msg, type=UPDATE (2), len=142

Clear Commands

Clear IP BGP

BGP sessions must be cleared for BGP policy changes, such as alterations to prefix list filters or actions

taken by a route map, to take effect. Use the clear ip bgp command to clear BGP neighbors as specified:

#clear ip bgp [* | <number> | <ipv4 address>] [in | out | soft]

* Clears all BGP neighbors.

<number> Clears all BGP neighbors with the specified AS number. Range is 1 to 4294967295.

<ipv4 address> Clears the BGP neighbor with the specified IPv4 address. IPv4 addresses should be

expressed in dotted decimal notation (for example, 10.10.10.1).

in Causes a soft reset inbound with a neighbor, reprocessing routes advertised by that neighbor.

out Causes a soft reset outbound with a neighbor, resending advertised routes to that neighbor.

soft Causes a soft reset both inbound and outbound.

Turning on a large amount of debug information can adversely affect the performance of

your unit.

If no arguments are given, the debug ip bgp command displays general BGP events, such

as sent/received message summaries, route processing actions, and results. Keepalive

packets are not debugged with this command.