Identify active network connection and change DNS server

Hey guys,

I need to run a script on several computers that can identify the active network connection, then for each one of them:

- if the network connection is not using DHCP (fixed IP address), change the current DNS server to another one
- if the network connection is using DHCP, do nothing.

I don't know the names of the network connections on the different computers, so the script has to find this by itself.

I've been searching about this but I'm having troubles finding a working solutions.

Any help would be greatly appreciated!

TIA