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Web server and router problem WEIRD

Hello everyone,

I have a weird problem that I want to share, so that someone more expert can tell me why this problem occurs.

I have a small home network, with a gateway/router/adsl modem connected to the internet (USRobotics 9106). Two pcs are connected to this device..

The gateway's IP is 192.168.1.1 while the pcs are 192.168.1.11 and

192.168.1.12. No DHCP. The pcs are configured with their fixed ips and the gateway/DSN server set to 192.168.1.1. Everything works fine, both the pcs can access the internet for surfing and email receiving.

On one of these two pcs I have installed a webserver, that I have set up to listen to port 81. In the gateway's virutal servers configuration, I have set the TCP incoming traffic on port 81 for the pc with the webserver.

The webserver works fine when someone else surfs on it using my WAN external ip address (I've tried it with friends, with http://xxx.xxx.xxx.xxx:81)PROBLEM : I can surf on it from my network only if I use the LAN ip of the webserver (http://192.168.1.12:81) and NOT the external WAN ip.

If I try using the wan external ip address, I cannot reach the web server. It's strange because if I try accessing the server via a free proxy

formatting link
etc) I can see that the server is up and working, but when I try to surf on it directly, I simply can't.

It has probably something to do with the gateway, because I have tried to access the internet with an old traditional plain modem without router, and when I use that, the webserver is reachable also using the external wan ip address.

How can this be ? I hope you didn't fall asleep while reading this message :-)

Thank you for your help Mirko

Reply to
mirko4u
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Most likly because your router/firewall is port forwarding from the WAN side and not the LAN. You need to access it on the LAN using the LAN address.

Reply to
chris

You can't address or access the external or public facing IP from and machine behind the router. That's not going to work. You must use the LAN IP that the Web server is using to access the machine from another machine on the LAN. You use Localhost to access the Web server from the Web server itself.

Duane :)

Reply to
Mr. Arnold4

You can't address or access the external or public facing IP from a machine behind the router.

Duane :)

Reply to
Mr. Arnold4

This is not weird - this is something working as it is supposed to

- outsiders connect to your ISP provided ip address and are allowed through to the server. ( it would help to know what server and how it is configured.)

- when you got to a proxy server, you 'transfer' yourself outside, then you are coming in as an outsider

- when you connect from inside, your local network has no knowledge of your ISP provided ip address, so it can't find the server. that address is for internet use only, and is known only by your router

- your local network does know about 192.168.0.12:81 and gladly connects to it.

Stuart

Reply to
Stuart Miller

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