Check System Logging

Purpose

By looking through the messages file for any entries pertaining to the interface that you are interested in, you can further investigate a problem with an interface.

Action

To check system logging, use the following JUNOS CLI operational mode command:

user@host> show log messages | match interface-name

Sample Output

user@host> show log messages | match so-0/3/1 

May 2 12:10:58 router rpd[729]: RPD_ISIS_ADJDOWN: IS-IS lost L2 adjacency to ABC-CORE-RTR1 on 
so-0/3/1.0, reason: Interface Down

May 2 12:11:27 router mib2d[575]: SNMP_TRAP_LINK_DOWN: ifIndex 25, ifAdminStatus up(1), ifOperStatus 
down(2), ifName so-0/3/1

May 2 12:11:27 router rpd[729]: RPD_ISIS_ADJDOWN: IS-IS lost L2 adjacency to ABC-CORE-RTR1 on 
so-0/3/1.0, reason: Interface Down

May 2 12:11:31 router rpd[729]: RPD_LDP_NBRDOWN: LDP neighbor 130.81.4.109 (so-0/3/1.0) is down

What It Means

The sample output shows entries in the messages file pertaining to the SONET interface, so-0/3/1, and its Intermediate System-to-Intermediate System (IS-IS) adjacencies and Label Distribution Protocol (LDP) neighbors. The entries indicate that the interface went down on May 2 at 12:11:27, and that both the IS-IS adjacency and the LDP neighbor are down.