Thin wrapper around ssh and netcat to check network connectivity.
$ fwcheck localhost:81
[OK] localhost -> localhost:81 OK! (closed port)
$ fwcheck 10.219.27.1 example.com:80
[OK] 10.219.27.1 -> example.com:80 (open port)
$ ./fwcheck 10.219.27.1 example.com:81
[FAILED] 10.219.27.1 -> example.com:81 (timeout)