/usr/bin/rup
You should get output on each of the stations on your network. The other stations on your network must be up for your station to get a user-friendly response. If the other stations are powered on and attached to the network but not up in user mode, the information comes back in hexadecimal.
/usr/etc/ping station_name
Let the output run a few seconds, then use <Ctrl-C> to break it. Pay particular attention to the ping statistics. ping gives you the number of packets transmitted, number of packets received, percentage packet loss, and round trip time (minimum, maximum, and average). These are all good indicators as to the general condition of your network. Obviously, you want 0% packet loss and a fast round-trip time.