The Port field for Remote/TCP & GDBServer/TCP can't be changed.
Trying cvs trunk avr-insight on Fedora20 x86_64. After fixing a few
compiler errors (see
https://sourceware.org/ml/insight/2014-q1/msg00015.html), I'm finding
out that I can't change the Field "Port:", bth in "File\Target Settings"
and "Run/Connect to Target", when selecting the "Target:" as
"Remote/TCP" or "GDBServer/TCP". The "Hostname:" field can be changed ok