Error trying to get SNMP info from Cisco switches

[DanMIS]

I just installed MRTG v2.14.3 on an IIS server. It allows me to connect to several switches, but not others. The others fail with the same error:

SNMP Error:
no response received
SNMPv1_Session (remote host: "10.53.4.3" [10.53.4.3].161)
community: "public"
request ID: 963135037
PDU bufsize: 8000 bytes
timeout: 2s
retries: 5
backoff: 1)
at C:/mrtg-2.14.3/bin\..\lib\mrtg2/SNMP_util.pm line 627
SNMPWALK Problem for 1.3.6.1.2.1.1 on public@10.53.4.3::::::v4only
at cfgmaker line 916
WARNING: Skipping public@10.53.4.3: as no info could be retrieved

I tried using the RW password as well as the RO, and verified on the switch that the passwords were correct. I'm stumped.

Any help would be appreciated!

Thank you,
Dan

 

[nbowden]

Hi,

If your community strings are definitely correct, then the only other thing that I can think of is an ACL applied to the 'snmp-server community' commands of your Cisco routers ?

Its quite common to protect your snmp using ACL's to stop anyone from doing an SNMP query on your routers (even if they have the correct community string).

If an ACL is applied, your snmp statement will look something like :

snmp-server community public RO 10

The '10' is the number of the applied ACL.

The only other thing that I can think of it to check the case of the community string ? PuBlIc and public are not the same for SNMP...

HTH


Nigel Bowden

http://www.bowden-software.com

 

[DanMIS]

Thanks for the reply, Nigel. I double checked, and there are no ACL's in place for SNMP and the passwords are in the correct case.

 

[nbowden]

Hi,

Not too sure what the issue is then...

You might like to download an SNMP tool such as Net-SNMP (

http://net-snmp.sourceforge.net/)

and try to do an snmp get command from the command line :

snmpget -v 1 -c public 127.0.0.1 1.3.6.1.2.1.1.1.0

This way, you can see if you have an SNMP connectivity issue, or an issue with MRTG.

HTH


Nigel Bowden

http://www.bowden-software.com

 

[DanMIS]

I downloaded Getif and eventually (embarassed look) realized that the problem wasn't with SNMP, it was with Vlan1. The last line in the configuration for Vlan1 was "shutdown".

Removing that solved all my woes. Lost sight of the forest because of the trees.

Thanks for your help anyway, Nigel.

Dan