check_udp (openVPN) sent string issue


Hi, I’m currently having trouble trying to get the check_udp nagios plug-in to get a response from openVPN.

I am using Nagios(3.0.6) and openVPN is set up listening on port 1194, but my problem is that check_udp requires both a sent / expect string.

This is the command i am using and the response i get:

check_udp -H localhost -p 1194 -s “openvpn” -e “ok” -v
Using service UDP
Port: 1194
flags: 0x2
Send string: openvpn
server_expect_count: 1
0: ok
CRITICAL - Socket timeout after 10 seconds

Basically i have spent 2 days trying to find out what string openVPN is waiting for so that it will give me a response to show that it is accepting connections on that port.

So if anyone can tell me what i need to put in -s " " -e " " i would be eternally grateful since google refuses to give me a solution.


I have the same problem with getting strings. im trying to check my radius udp port. Did you found anny solution?


i don’t know for openVPN but there IS a check_radius plugin.


I know thx, but im not allowed to used it. Im a student and doing this at school. There are not willing to give passwords that i need.


try having a look at this post: … 00264.html

Hope it helps.