Check snmp follow.pl
Introduction
Use this script to look for a value in an snmp table.
Suppose you have an snmp table called hardwarestatus that looks like this:
Table:
Index name status 1 cpu good(1) 2 hdd1 good(1) 3 hdd2 good(1) 4 gpu good(1)
Or if you did a walk you would see:
.1.2.1.1 = 1 .1.2.1.2 = 2 .1.2.1.3 = 3 .1.2.1.4 = 4 .1.2.2.1 = cpu .1.2.2.2 = hdd1 .1.2.2.3 = hdd2 .1.2.2.4 = gpu .1.2.3.1 = good(1) .1.2.3.2 = good(1) .1.2.3.3 = good(1) .1.2.3.4 = good(1)
Now you want to monitor the temperature of the gpu. You figure the oid for the gpu is .1.2.3.4. So you whip up a nagios monitor that looks like this:
check_snmp.pl -H myhost -c public -o .1.2.3.4 -r 1
But then a hdd is added and the table looks like this:
Index(1) name(2) status(3) 1 cpu good(1) 2 hdd1 good(1) 3 hdd2 good(1) 4 hdd3 good(1) 5 gpu good(1)
Now your gpu is in snmp index 5 and you have to go and update all your nagios monitors, BLEH.
What if you could say: find the entry that is called "gpu" and check it's status?
That is check_snmp_follow.pl.
use it like this:
- oid1 is the column you should grep for a value , in this case oid1 should be .1.2.2 (name)
- string is "gpu"
- oid2 is the column you will find your interesting value in. In this case oid2 should be .1.2.3 (status)
- r the value to go green, in this case 1 ( good )
the nagios command would be:
/usr/local/nagios/libexec/check_snmp_follow.pl -comm public -H 10.21.255.1 -oid1 .1.2.2 -string gpu -oid2 .1.2.3 -r 1
The result would be:
OK: 1
So now we don't care what snmp index the gpu shows up on, nagios will follow it around.
Here's an example I'm using to monitor an ipsec tunnel on the ASA.
/usr/local/nagios/libexec/check_snmp_follow.pl -comm XXX -H 10.21.255.1 -oid1 .1.3.6.1.4.1.9.9.171.1.2.3.1.7 -string 131.104.91.242 -oid2 .1.3.6.1.4.1.9.9.171.1.2.3.1.35 -r 1
no matter what index the "131.104.91.242" endpoint shows up in, we will examine it's "status" field ( .1.3.6.1.4.1.9.9.171.1.2.3.1.35.X )
Nagios Setup
in command.cfg
define command{
command_name check_snmp_follow
command_line $USER1$/check_snmp_follow.pl -comm $ARG1$ -H $HOSTADDRESS$ -oid1 $ARG2$ -oid2 $ARG3$ -string $ARG4$ -r $ARG5$
}
in z-sms-bell-asa-fw.cfg
define service{
use generic-service
host_name tor1-asa1
service_description 3-22-d-cikeTunStatus-UofG
check_command check_snmp_follow!eeTo3Zoo!.1.3.6.1.4.1.9.9.171.1.2.3.1.7!.1.3.6.1.4.1.9.9.171.1.2.3.1.35!131.104.91.242!1
}
