external IP... hmmm ... you have external IP when you dont connect to the internet through router or someones computer and your IP doesnt change every time you connect other way to say it there are 2 types of IP... internal and external... in your LAN you use internal IP... when you want to access to the internet you use external IP... if your computer is in LAN net, it use IP of getaway (cuz it connects through getaway; it can be named: gate, proxy server; every person in LAN network who want to connect to the internet use same external IP) and now people from your LAN who want connect to your computer use your internal IP... if some one who want to connect to your computer from internet he/she use external IP of your getaway and if getaway is not configured properly it reject connection however if internet provider of your LAN network gives you dynamic IP (this IP changes every restart of getaway) you cant use it to host servers that means if you are connecting directly to internet you must check on your internet provider webpage if he offers you external IP... if you are connecting to internet through getaway you must ask your LAN network admin if he could give you external IP and open (for eg) 1234 PORT... than when you start hosting type in Host World window PORT: 1234; why doing this? cuz some getaways have firewalls built in and those blocks most of ports regards
PS about dynamic IP: in my country (poland) dynamic IP cant be used like external IP PS2 sorry for my poor english
