I'm trying to use GeekTool (Mac pref pane… basically just embeds output of a shell command/script on the desktop… http://lifehacker.com/#!244026/geek-to-live–monitor-your-mac-and-more-with-geektool) to monitor a a remote machines/server, and I'm having some trouble determining how best to check if a machine is up/down.
I'm using no-ip as a free dns re-direct… but this only helps me with the public IP of the router. The machine I want is behind the router and thus isn't able to be "ping"ed directly.
I have port forwarding set up for port 8080 which leads to the machine I want. Is there a way to essentially ping through port 8080 to see if the machine is up and running? I tried telnet, but this apparently doesn't work (as far as output) in GeekTool. I'm running a website at 8080, so I guess I just want to know if/when it goes down.
Thanks in advance… if I can provide more clarification let me know.
(figured out my problem… see below)
Best Answer
To check a specific port, you can use telnet:
(The port follows the IP / hostname with a space, not a colon.)
If you get an immediate error, then the port is not available. If telnet hangs, then you have successfully connected to the port. Ctrl + C to kill telnet, then.
This may or may not help with the port forwarding issue, though. It just gets you to that IP and port.