Description

We see the trap being sent from Cisco devices using the BRIDGE-MIB with an OID of 1.3.6.1.2.1.17.0.1. The MIB has the trap listed as 1.3.6.1.2.1.17.1. I have looked at multiple Juniper switches and they don't appear to send any trap when the root bridge changes. We have enabled the following trap categories set snmp trap-group itsarostring categories chassis set snmp trap-group itsarostring categories link set snmp trap-group itsarostring categories remote-operations set snmp trap-group itsarostring categories routing set snmp trap-group itsarostring categories startup set snmp trap-group itsarostring categories vrrp-events set snmp trap-group itsarostring categories configuration set snmp trap-group itsarostring categories services

Solution

No new rootbridge has been elected, This is the reason why the SNMP walk is not properly sending the expected output. Advised reproducing the issue, meaning to get a new root bridge and run "show snmp walk mib 1.3.6.1.2.1.17.0.1" again

 

show snmp mib get 1.3.6.1.2.1.17.0.1 

newRoot          No such object >>>> no new root bridge has been elected.

 

show snmp mib walk 1 | match dot1dBaseBridgeAddress                                                                              
dot1dBaseBridgeAddress.0 =XX XX XX AA BB CC
  • The above is the actual bridge ID:

 

root@switch> show spanning-tree bridge detail
STP bridge parameters
Routing instance name        : GLOBAL
Context ID             : 0
Enabled protocol          : RSTP
 Root ID              : 8193.00:23:04:ee:be:01
 Root cost             : 10000
 Root port             : ae0
 Hello time            : 2 seconds
 Maximum age            : 20 seconds
 Forward delay           : 15 seconds
 Message age            : 1
 Number of topology changes    : 1
 Time since last topology change  : 2304982 seconds
 Local parameters
  Bridge ID            : 32768.XX XX XX AA BB CC
  Extended system ID       : 0
  Hello time           : 2 seconds
  Maximum age           : 20 seconds
  Forward delay          : 15 seconds
  Path cost method        : 32 bit

 

Important: After changing STP root bridge, the snmp trap was properly sent on the OID expected.

Modification History

2024-04-19 : Article Created