[Nagiosplug-help] check_snmp wierdness

[Peter Pauly]

I'm using check_snmp to check the status of the interfaces on Cisco
routers, and for the most part, it is working well. However, I have
one interface that Nagios is reporting as down, despite the fact that:

1. Running check_snmp by hand shows the interface is up:

/usr/lib/nagios/plugins/check_snmp -H xx.xx.xx.xx -C xxxxxxx -o
ifOperStatus.21 -r 1 -m RFC1213-MIB
SNMP OK - up(1) | RFC1213-MIB::ifOperStatus.21=up(1)

2. The router being checked shows the interface is up (via cisco commands)

3. Running snmpwalk and dumping the whole shebang shows the interface is up.

My environment is:
Nagios 3.0.2 from the packages
Ubuntu 8.10

I'd rather not install Nagios 3.04 from tar. When you have to
administer 100 servers, you try to keep things as simple as possible
;).

The definition for the failing check is:

define service{
use generic-service
host_name xxxxxx
service_description xxxxxxxxx
check_command check_snmp!-C xxxxxxx -o
ifOperStatus.21 -r 1 -m RFC1213-MIB
contact_groups xxxxx,yyyyyy
}

which, except for the interface number "21", is the same as all of the
working ones.