Virtual Server on port 80

[ruprecht]

Hi, I've been using Virtual Server successfully for months, forwarding ports for games etc into my LAN. I've just started using it for a Linux server and am having problems with port 80. Forwarding SSH and FTP on 22 and 21 respectively to the box works fine, but 80 doesn't. When I forward 81 instead and config my webserver to listen on 81, it works fine. It's ONLY port 80 that can't seem to forward. I've checked with my ISP and they are not blocking 80. What is wrong with my bloody router?
Thanks

[unaiur]

What firmware version do you have? Can you post your firewall rules?
Go to http://my.router/Main_AdmStatus_Content.asp and type "iptables -L -v -n " (without quotes)

[ruprecht]

Hi unaiur
I will check the firmware version and firewall rules tonight and post here. I updated to the latest binary release on the ASUS site last night.
Thanks for the quick reply.

[ruprecht]

My ISP suggested that maybe because the router web configuration runs on 80 it's unable to forward 80. Is it possible to change the port that the web configuration runs on?

[unaiur]

Linux is capable to do so. Traffic comming from the wan can be redirected to an internal webserver while traffic from the lan arrives to the administration web page. I don't know if the web interface is also capable, but the great Oleg's firmwares can do it (using telnet, the command line and a text editor, of course).

[ruprecht]

OK my firmware version is 1.9.4.0.

The Port forwarding page in the web interface shows the following ports redirected:

Destination Proto. Port Range Redirect to
203.etc TCP 22 192.168.etc
203.etc TCP 21 192.168.etc
203.etc TCP 80 192.168.etc
Running the iptables -L -v -n command gives me nothing. The screen just refreshes and there's nothing displayed.

I haven't been able to find anywhere to change the default port for the web interface.

[ruprecht]

I restored to default settings, and even that didn't help. Should I switch to one of these custom firmwares? Anyone know how I would fix the issue with a custom firmware?

[unaiur]

The iptables command works in Oleg's firmwares, that is what I use and works fine. The extra ports shown at the forwarding page can be generated by the "Port Trigger" feature.

[ruprecht]

OK I have upgraded to Oleg's 1.9.2.7-6b

I have set it up again with virtual server forwarding 80 to local Ip 192.168.1.197 on 80. the iptables command via telnet reveals the following in chain FORWARD:

0 0 ACCEPT tcp -- * * 0.0.0.0/0 192.168.1.197 tcp dpt:80
0 0 ACCEPT tcp -- * * 0.0.0.0/0 192.168.1.197 tcp dpt:22

SSH works, http does not. Any ideas?

[ruprecht]

OK, i fixed it!
Turns out the problem was my D-Link DSL-300G ADSL modem that was plugged into the router. The modem blocks inbound 80 and 23 by default
http://martybugs.net/smoothwall/dsl300g_ports.cgi
Thanks for the help mate