I'm not familiar with the CurrPorts application, but I believe that it is showing what the application is listening / bound to. 0.0.0.0 is commonly used to denote any local address. In order words, Factorio is listening for any UDP packets on port 34197, regardless of which local IP they arrive on ...

A local IP address would most commonly be in the following format:
10.***.***.***
172.***.***.***
192.168.***.***

Make sure you're forwarding UDP rather than TCP.

I have found this though http://puu.sh/npSr7/796f8d3a61.png

I don't know whether this is common but it is not using the IP I have ...

Are you sure your IP is public and you are providing the global, not local IP to your friend?

Lot of these problems will be solved by the matching server in 0.13.

Yes I am using my external IP address, have got it linked up to a dynamic DNS service and domain. Have a teamspeak server running ...

Same problem right here, unable to run headless server from Steam directory.

I have been loving Factorio, big ups to the devs really good game.
I have tried to set up a multiplayer server and port forwarded port 34197. I am sure my ISP is not blocking this port.
My friend is not able to play with me although my brother in the same network can play with me.
Someone on reddit ...