Local IP address?

[Dave M G]

Ubuntu Users,

This seems to be one of those questions so simple that no one feels the 
need to provide the information.

I want to know how to be able to find out what my *local* IP address is. 
I have a router which automatically assigns an IP address to each 
computer hooked into it. I know my computer is in the range of 
192.168.0.???. But the last number is something between 1 and 4, and I'm 
not sure what.

I've looked around on the net and I can easily find out my address as 
seen from out on the internet, some completely random, dynamically 
number assigned at my Internet Provider. But that's not what I need to know.

I need to know exactly what my LAN IP address is so that I can assign 
port forwarding to my computer.

So, how do I do that?

Thank you for any instruction.

--
Dave M G