When clicked on IPv4 address in terminal window, it gets selected as a whole, not a single octet. The same action does not work for IPv6 adress, it does not get selected. I assume there is some setting for IPv4, in terminal settings. I could not figure it out, though. Can I make click selection for IPv6 to work?
This isn't just a Terminal thing, this is an OS X selection thing. Anywhere in OS X where auto-range selection works, it will select an IPv4 in that way. As far as I am aware, there is no way to customize this as it is part of the OS.