in reply to Tk app to show the computers you are connecting to

Nice work. Runs fine on RedHat 6.x

Column headers for the "Current connections" windows would be nice, for those who didn't write the app.

Line 68: make that a parameter, or check for /etc/resolv.conf and get the value from there.

Line 134: right.

There's a classic blunder at line 143: check to see if the regexp actually matched before you use $4 elsewhere.

At 157, you should check to see if $connlist[$i]{rip} is defined before using it as a hash element. Also, the () around an unless or if modifier aren't necessary.

Line 218, assign a default value to $portnum to avoid another undefined value error.

And so on. Some basic cleanup before posting is a nice thing, but it's a good start.