Internal Ip as a server IP :S

Ok i have no idea what i did cause i had a multiplayer working the other day.
However, this time i made it just how i did last time by clicking on create multiplayer and invited my friend and it didn’t work. I noticed that the Ip address for the server was an internal Ip address so how can i fix this.

Thanks for all the help to come.

Go onto any whois site and find your own IP. For example http://cqcounter.com/whois/

You can then give your friend that IP to search for.

I tried giving him the IP address that appeared in the garrys mod Console that wasn’t and external one. But it still didn’t work.