Cisco IOS XR SNMP Bug

[michellebperez]

Does anyone knows if using the command 'snmp-server ifmib stats cache' on a cisco IOS - XR, version 4.0.3 can cause any kind of crash on the equipment?

I've searched on the release notes for this version but there wasn't any bug's registered for SNMP cache.

I had this command applied on a cisco device and this device crashed, after removing this line the device started responding again.

[tkarnani]

It is strange that this command would cause a router to crash.(by crash i am assuming a reload)

do you have the log messages before the reload?

it would be helpful to see what errors were displayed before the reload

[michellebperez]

Unfortunaly I don't, the equipment didn't actually reloaded,he just started responding very slow and the snmp server couldn't collect anything from the router, stoped reaching it and only responded again when the command was removed.

I think it could have been a coincidence the removal of the command resulting in the router responding again, but before enabling it again I wanted to be sure that there is not a bug related to it that could causa this to happen again.

My IOS version is old and is already out-of-sale, so I don't find to many info about it.

Already read the release notes from the version and didn't found any bug related with the caching.

Also, if you know, I saw the consulting of the caching for this command was only released on version 5.2.2, through 'show snmp mib ifmib general' and 'show snmp mib ifmib cache'. Is there any other way for me to confirm that the statistics are being collected from the cache and not real time in the old version 4.0.3?

[tkarnani]

We can check the following command

show snmp mib statistics

This should provide us a list of OIDs that take long to complete (greater than 1 second). After enabling ifmib cache we should see an improvement.

That is one method i can think of..

[michellebperez]

Those are the only outputs that I can see from show snmp, can't see snmp mib statistics. Do you know any other command?

RP/0/RSP0/CPU0:HOSTNAME#show snmp ?
context-mapping Show the context-mapping
correlator Show the content and info about correlator buffer
engineid SNMPv3 engineID
entity Show ENTITY-MIB entPhysicalName and entPhysicalIndex. Execute from same node where snmpd is placed.
group SNMPv3 groups
host SNMPv3 hosts
interface SNMP Interface properties
mib SNMP supported MIB objects
request SNMP received requests information
users SNMPv3 users
view SNMPv3 views
| Output Modifiers
<cr>
RP/0/RSP0/CPU0:HOSTNAME#show snmp mib ?
access SNMP Object Access information
dll SNMP MIB DLLs
object-name SNMP supported MIB object names
| Output Modifiers
<cr>

[tkarnani · Accepted solution]

It looks like that command may not be present in your code.

I am not sure what else can be checked in that case.