[Nagiosplug-help] How to format send/expect strings for check_udp against SNMP managed devices?

[Andreas Ericsson]

Ralph.Grothe at itdz-berlin.de wrote:
> Hi Tom,
> 
> you are absolutely right.
> 
> I simply forgot that according to SNMP RFCs every vendor is
> demanded to furnish
> with its own MIB extensions a minimal set of standard leaf
> descriptors such as the sysDescr,
> if his product shall conform to the standards.
> 
> So, as you suggested I make a check_snmp of
> RFC1213-MIB::sysDescr.0 
> my default "check_host" for SNMP managed devices.
> 
> Btw. what form of invocation is to prefer?
> This one where I pass the MIB to load explicitly via -m

...

> or the more often used form with prepended MIB?
> 
 
The correct answer is "none of the above". Use the OID directly
instead. It's not subject to change. .1.3.6.1.2.1.1.1.0 is the
one you want, and will save quite a bit of load every time you
run the check.


> As the really executed snmpget command, which the -v option
> additionally displays, implies to me
> the second form seems to load ALL MIBs from net-snmp's mib dirs
> which to me seems to be more wasteful than the preselection via
> -m.
> Is this true?
> 

Yes. By default the Net-SNMP tools load all the mibs on every
invocation. You can limit the number of mibs to load using the
-m switch, and also tell it to load mibs from different locations.

"-m :" will make it load no mibs at all, which is what you want.
The check_snmp plugin will notice if you're using an oid or a
mib-name and act accordingly.

-- 
Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231