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Put TCP or UDP ports to listening in router

Hi, I would like to know if there are a way to configure a router, making the router let the TCP or UDP ports in listening, to test a connection trough a firewall.

For example: The router is with a TCP port 3200 in listenig, and when I go make a connection with a telnet extended (in DOS: c:> telnet [address] [port], the router responds if this connection is estabilished.

Any help is good..

tks

2 REPLIES
Silver

Re: Put TCP or UDP ports to listening in router

I beleive a sh tcp , or sh tcp br will show you this.

Gold

Re: Put TCP or UDP ports to listening in router

I don't know if there's an easier way, but here's one I was thinking about.

If you have Windows NT Server 4.0 or Windows 2000 Server you can set up a web site using Internet Information Server (IIS) on whatever TCP port number you want, from 1 to 65535. The web server listens on that port. You can even set up multiple web sites, each assigned to a different port number.

Then you can use a web browser to try to access "http://web.server.ip.address:portnumber". (You have to include the ":portnumber" in the URL or the browser assumes port 80.) Or, Telnet from the command line as you posted in your message.

This approach will work only for TCP. But if you know the access control lists or firewall rules are working for the TCP port, then you can assume it will work for the UDP port when you just change the protocol from TCP to UDP in the ACL or rule.

In the meantime, I will keep my eyes open for software that lets you emulate a TCP or UDP service at whatever port number you choose. I will post a link here if I find anything.

Hope this helps.

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