I am totally a network novice.
My plan is to do some simple low-bandwidth testing of a web server I have configured using Tomcat standalone technology. It runs on port 5050 and works as expected in "localhost" mode. My dlink dsl504T modem/router offers "port forwarding" to allow web users to access an IP address within the local network. The router has a fixed IP address and the router software allows one to divert designated port traffic to an local network IP address. The following entries were tried:
private IP: 10.1.1.3 (the computer running tomcat)
protocol: TCP (also offered UDP and BOTH)
port start: 80
port end: 80
port map: 5050
When an external web web user entered the fixed IP address of my router (preceded by "http://" prefix) there was no connection.
I am assuming that an http request coming to the router is received at port 80 by convention. I am assuming that router port 80 traffic is simply diverted to the local IP address and to port 5050 where tomcat is listening.
I have obviously got something wrong. Thanks if you can help.

Well first thing that comes to mind that you didn't state. Are you running a web-server on the machine that the traffic is being forwarded to? If not it could be getting requests but doesn't have anything to send back. Also remember when your in your testing phase you may have to turn off your security settings and start turning them on one by one until you are at your desired level of security.

Also I wouldn't recommend "assuming" the router is doing anything. It should be doing what you are telling it if the settings are correct, and forwarding traffic to the machine you designated as your web-server. Another thing you shouldn't need the http:// if you are trying to access directly through the router. Simply type the address of the router into the address bar.

thanks predator78, I am sure as you say, that "assuming" often leads to unsatisfactory results. I did have Tomcat running and generating a continuous log in a terminal window. I plan to try again with a new modem.

also, security settings may well be the problem. I need to get more familiar with these before I try again,

Yeah that was all I meant by not assuming. Yeah it's always wise when networking to lower security to get it working then raise the level once you know things are working correctly. Good luck with your project sounds fun.

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