I am trying to use the Check_sip plugin from www.bashton.com (seems to be the common one to use). I am having two problems however.
The first is this: When I run the command
check_sip -u firstname.lastname@example.org -H some.ip.address -p 5060 -w 2
from the command line, it works fine, and returns with an OK response. When I type that very same line into my checkcommands.cfg file, Nagios reports the status as 'No Output".
The second problem that I am having is when I run that same command using a different SIP server, it returns the error, "Invalid Extension".
Does anybody have any experience with the check_sip plugin that may be of some help?