To enable logging of BGP neighbor resets, use the bgp log-neighbor-changes router configuration command. To disable the logging of changes in BGP neighbor adjacencies, use the no form of this command.
bgp log-neighbor-changes
no bgp log-neighbor-changes
This command has no arguments or keywords.
No BGP neighbor changes are logged.
Router configuration
| Release | Modification | 11.1CC and 12.0 | This command was introduced. |
|---|
The bgp log-neighbor-changes command enables logging of BGP neighbor status changes (up or down) and resets for troubleshooting network connectivity problems and measuring network stability. Unexpected neighbor resets might indicate high error rates or high packet loss in the network and should be investigated.
Using the bgp log-neighbor-changes command to enable status change message logging does not create a significant performance hit, unlike, for example, enabling per BGP update debugging. If the UNIX syslog facility is enabled, messages are sent to the UNIX host running the syslog daemon so that the messages can be stored and archived. If the UNIX syslog facility is not enabled, the status change messages are retained in the router's internal buffer, and are not stored to disk. You can set the size of this buffer, which is dependent upon the available RAM, using the logging buffered command.
The neighbor status change messages are not tracked if bgp log-neighbor changes is not enabled, except for the reset reason, which is always available as output of the show ip bgp neighbor command.
The log messages display the following reasons for changes in a neighbor's status:
BGP protocol initialization
No memory for path entry
No memory for attribute entry
No memory for prefix entry
No memory for aggregate entry
No memory for dampening info
No memory for BGP updates
BGP Notification received
Erroneous BGP Update received
User reset request
Peer timeout
Password change
Error during connection collision
Peer closing down the session
Peer exceeding maximum prefix limit
Interface flap
Router ID changed
Neighbor deleted
Member added to peergroup
Administratively shutdown
Remote AS changed
RR client configuration modification
Soft reconfiguration modification
The eigrp log-neighbor-changes command enables logging of Enhanced IGRP neighbor adjacencies, but messages for BGP neighbors are logged only if they are specifically enabled with the bgp log-neighbor-changes command.
Use the show logging command to display the log for the BGP neighbor changes.
The following configuration will log neighbor changes for BGP:
bgp router 100
bgp log-neighbor-changes| Command | Description |
|---|---|
| logging buffered | Enables logging of message to an internal buffer. |
| show ip bgp neighbors | Displays information about the TCP and BGP connections to neighbors. |
| show logging | Displays the state of logging (syslog). |
Printed for apswan@ctr.ap.nic.in on Wed Mar 5 22:32:57 PST 2003
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