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
(www.phproxy.org, 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

Re: Web server and router problem WEIRD

wrote in message
news:1163972120.168073.72070@f16g2000cwb.googlegroups.com...
> 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
> (www.phproxy.org, 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
>

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.

Re: Web server and router problem WEIRD

mirko4u@gmail.com wrote:
> 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
> (www.phproxy.org, 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 :-)
>

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 :)

Re: Web server and router problem WEIRD

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

Duane :)

Re: Web server and router problem WEIRD

wrote in message
news:1163972120.168073.72070@f16g2000cwb.googlegroups.com...
> 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
> (www.phproxy.org, 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
>
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