Working with non-mib2 snmp agents

[mpissioli]

Hi

I´m a new user here and first I want to say that Cacti is amazing!

Now the problem: I´m working with some proprietary contact center servers that have non-mib2 snmp agents running, i.e, the agents will not respond to sysUptime, sysLocation, etc...

I´ve tried to create a real simple data query (snmp indexed) using other examples as templates for those systems but the result is always the same:

Running data query [10].
+ Found type = '3' [snmp query].
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/ccms-common-ivr-v8_disk.xml'
+ XML file parsed ok.
+ Executing SNMP walk for list of indexes @ '.1.3.6.1.4.1.6889.1.20.1.2.5.1.1'
+ No SNMP data returned
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/ccms-common-ivr-v8_disk.xml'
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/ccms-common-ivr-v8_disk.xml'
+ Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/ccms-common-ivr-v8_disk.xml'

The xml is parsed ok.

Walking the mib with external snmpwalk or snmpbulkwalk, I´m able to collect the info I need, but the problem seems to be the php-snmp support used by Cacti.

My question is - the fact that the agent running on the server is not a mib2 compliant agent (i.e. it just respond to enterprise oids) makes it incompatible to Cacti? Is this a limitation of php-snmp, which will always poll for mib2 oids before polling the target oids when walking?

Please, any help will be appreciated.

Thanks in advance.

Mauricio

[gandalf]

The answer is twofold:
You defined a Device/Host to tell cacti about the remote system. Cacti will perform some Downed Host Detection based on generic settings (e.g. PING(ICMP, UDP), SNMP, both) and will continue to query the system only if this succeeds. To come around that, the only option is to leave the community string of that device empty. Then no downed host detection will be performed.
Second: cacti does not rely on MIBs, it only takes OIDs. To verify correct performance, please

Code: Select all

snmpwalk -c <community> -v 1 <target> .1.3.6.1.4.1.6889.1.20.1.2.5.1.1

to verify that this OID returns results.
Reinhard

[mpissioli]

OK, I got it. I've discovered that the real problem that was preventing the snmpwalk to run properly was that SELINUX was enabled. With SELINUX enabled, the "apache" user is not allowed to exec applications through php (exec method) that opens ports <= 1024. So, the snmpbulkwalk, used to get the index, always fails.
I have disabled the SELINUX and things started to work correctly.

Thanks for your help.

Mauricio