Monitoring Teamspeak3 servers with check_teamspeak3 & Icinga2

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Just a short note as no one seems to really mention this. If you want to monitor your Teamspeak 3 server with Icinga2 (or Nagios or any other compatible monitoring system): check_teamspeak3 from xicon.eu / xiconfjs still works flawlessly despite the fact that the "Last commit" being 3 years old.

A little bit of background, or: UDP monitoring is hard

Teamspeak 3 - being a voice chat - utilizes UDP for most of it's services. Understandably as speed is key in providing enjoyable voice communications and simultaneously it can cope well with a few lost packets.

This however is the main problem in monitoring. With TCP you can open a simple TCP-Connect and if the port is open assume that your service is working. With UDP: You can't as UDP won't give you any feedback if any your packets were received as UDP in its entirety lacks the "Transmission Control" part of TCP in favour of faster packet sending/progressing. Therefore you have to send a request that provokes an reply and thus enables you to check that reply against your expected "Known good/working" reply.

This means that you must delve into the depths of a protocol in order to know what your packets must include. And this is the part where it often gets complicated, time-consuming and cumbersome. More often than not people rather went with a "Let's just check if the process is running." or "If the application opens a TCP-port too, let's just check that one." solution.

I however wanted a detailed check and check_teamspeak3 exactly does this. It connects to the voice datagram port and sends the appropriate encoded UDP packets and checks the result. Et voilà we have a monitoring check that really checks the working condition.

Thanks xiconfjs!

Alternatives

For those coming here in order to search for other ways to monitor Teamspeak 3: You can of course do one of the following:

• Check if the Teamspeak process is running
• Examine the list of locally opened ports and check if the ports are in listening mode (lsof, netstat, etc.)
• Expose the serverquery port and do your checks via commands (see: https://community.teamspeak.com/t/how-to-use-the-server-query/25386)
• The FileTransfer part of Teamspeak uses a TCP port, you could verify that this port is open with a simple check_tcp servicecheck