How can I know the real IP address with which I appear on th internet.
The problem is that I want to give ftp access for my brother accross
the internet to my machine. But he can't connect to me because I
only know the local ip address (192.somthing). I get my IP address
using DHCP, I have DSL connection in my room which I get from
another flat. So I don't know what happens exactly in the other flat
(I mean I don't know how's the network setup). But I guess there is
a DSL modem and a router.
I am a complete , so please be patient with me
I am using Debian by the way.

Thanx in advance.