SNMP Errors After Upgrade

michaeln · Post by **michaeln** » Fri May 27, 2011 5:49 am

We've been using Hostmonitor 4.70 for quite some time and have been reluctant to upgrade to 8.8 out of fear and ignorance. Last night, we gave it a try but a few of our tests were mysteriously not working, particularly some SNMP tests.

snmpd.conf

pass .1.3.6.1.4.1.2021.302 /home/hostmon/bin/incoming

# snmpget -v1 -chostmon1 localhost .1.3.6.1.4.1.2021.302
UCD-SNMP-MIB::ucdavis.252 = INTEGER: 41

While this works on 4.70, when this test is run on the newest Hostmonitor, I get "SNMP: No value returned". Other SNMP tests, like the standard disk space checks, work just fine.

KS-Soft Europe · Post by **KS-Soft Europe** » Fri May 27, 2011 9:09 am

Could you please check Automatically append the single instance sub-identifier (".0") option, located on Misc page of Options dialog ?
If it is marked, please unmark it and try to refresh test.

michaeln · Post by **michaeln** » Fri May 27, 2011 10:23 am

No, that did not fix things. I actually read that in previous threads and tried that before posting here but it did not work. I also tried appending a .0 at the end as well to the OID, which also did not help. Any other suggestions?

KS-Soft · Post by **KS-Soft** » Sat May 28, 2011 11:05 am

I cannot find description of this OID (1.3.6.1.4.1.2021.302)
http://www.oidview.com/mibs/2021/UCD-SNMP-MIB.html
Could you please provide MIB file that describes this OID?

I assume OID is incorrect (e.g. this is not a counter but a table so you should add index of the element). When you request incorrect OID using SNMP GET request, some SNMP agents may return nearest correct counter (just like in response to GET NEXT request).

Old HostMonitor uses Windows API and may accept such response. New HostMonitor uses our own code (there are several bugs in Windows API related to SNMP protocol) and it requires correct OID. If agent returns different than requested OID, HostMonitor does not accept it.

Regards
Alex

michaeln · Post by **michaeln** » Mon May 30, 2011 5:58 pm

Just so everyone knows, you were correct in that the agent was not returning the same OID that was requested. The old client apparently did not care that this was the case, but once we fixed them so that they matched, this worked perfectly again. Thanks so much!

KS-Soft · Post by **KS-Soft** » Mon May 30, 2011 6:24 pm

You are welcome

Regards
Alex