NR041 port 80 forwarding problem w/ and w/o UPnP 1

[eremi]

I'm having a weird problem that I can't resolve since a month now.

My Network Everywhere NR041 router is always forwarding the port 80 to the computer I don't want to.

My roommate and me have 4 computers attached to the router. I have two PCs, one with Red Hat Linux 9 and the other with Windows XP. My roommate has PC and a Xbox.

The issue is with my two PCs and the router. The Linux PC always has the internal IP 192.168.1.100. My Windows has a different one.

I want to forward port 80 to the Linux PC. When I got the router, it was always working well... but not anymore.

Now, no matter what internal IP my Windows PC gets, the port 80 gets always forwarded to the Windows PC. I'm not sure why. I uninstalled IIS from it, and I also disabled UPnP on both the PC and my router, and I rebooted everything (all PCs and the router), but nothing will work.

All other forwarded ports work just fine!

Any ideas?

 

[bcastner]

Do you have DHCP enabled?

192.168.1.100 is in the default DHCP scope. This is not advised.

But you should check for new firmware for the router.

 

[eremi]

I have DHCP enabled, but I don't see what DHCP has to do with my port forwarding... (I'm not very good at TCP/IP networking, by the way...)

And I did install the newest firmware for the router when I started to have this problem. I also resetted my router to factory settings, and it still didn't fix it.

Any other suggestions?

 

[bcastner]

Set the Linux box to a static ip of 192.168.1.2
Forward port 80 to that address.
Do not use static ips in the DHCP scope of .100--.149.

You can re-enable uPnP on the other boxes and the router.

I think the router was confused by the static assignment into its DHCP range.

 

[eremi]

Hmm... I pretty sure all IPs are dynamically assigned to all my PCs by DHCP... But I'll check tonight to make sure.

 

[bcastner]

Why not go all static and disable DHCP?

 

[eremi]

Okay, so I've done everything today...

Disabled DHCP. Set static IPs on all PCs... still nothing.

I just don't get why just the port 80 gets altered. Why all the other ports are working?!

 

[bcastner]

When you say port 80 gets altered, how do you tell?

If it appears in the forwarding table, only a manual edit would change it.

If it appears in the uPnP forwarding table, a client-side uPnP gateway entry would make this change. The change is made by the client, not at the router.

If it is detected because of port traffic to the wrong machine, it is likely that someone has a shortcut with a port specification; i.e.

http://www.yourdomain.com:8080

(or some other direct port assignment)

 

[eremi]

The URLs I give out does not have port specifications.

The only port forwarding table I have in my router is a UPnP port forwarding table, and it is set as the way I would want it to work. The port 80 is set to be forwarded to 192.168.1.100:80.

My Linux runs Apache. My Windows runs IIS. I can tell the port doesn't stay forwarded at 192.168.1.100 because I see the IIS "Under Construction" page when I type my external IP address!

And for UPnP clients... I've disabled everything related to UPnP on my Windows PC. I just don't know what to do anymore.

 

[bcastner]

Ah, the router does not do reverse forwards. You need to access the web page using the PC's machine LAN side IP to access it.

 

[eremi]

Okay, but what if I want other people to come on my Web server?

And why the other ports, like for FTP and Telnet, are working externally?

 

[bcastner]

When you FTP or Telnet you are connecting your LAN ip, through forwarding, to your external WAN IP, to a completely different WAN IP than yours.

This is not analogous to using the same WAN IP on both sides of the connection and expecting a reverse forward to your private LAN-side IP.

 

[eremi]

Yeah, but I'm trying to access my Web server from work. DIfferent WAN IP there. Still doesn't work! But I can access SSH, Telnet, FTP, and the rest without any problem...

 

[bcastner]

It may be that your ISP blocks port 80 at home. Many do, as your terms of service often specificly exclude server roles, and the Code Red stuff led to widespread blocking by ISPs of port 80 for residential customers.

Try assigning a different port on the server: 8080 is usually open. You can make this easier by using a DDNS service. Google it, many are free.

 

[eremi]

Okay, I'll try that...

But still, when I access my WAN IP, from work or from home, I get the IIS server instead of Apache.

It's not what I want, but it suggests that port 80 is not blocked. And it was working fine for months before!

 

[bcastner]

Do a hard reset of the router:

Write down your current configuration settings on the router, as it will be lost.

Hold in the reset button. The diag light will come on, after 20 or so seconds all the lights will flash. After another 20 or so seconds the diag light will go out. Release the reset button.

Turn the router off. Wait at least 1 minute. Turn the router on.

Reset all of your router's configuration, as you have put it back to its factory defaults.

 

[bcastner]

manarth made a good point in another post about Apache access on the LAN: You can always make a HOST file entry to resolve the address locally:

192.168.1.100 yourdomainname.com

where 192.168.1.100 is your apache server's LAN address

 

[eremi]

For my LAN, that is what I do, but I want to make my server accessible to the Internet.

I don't have time to do a hard reset right, but I will tonight, and we'll see then...

 

[kennz]

eremi,

after trying a hard reset and it still does not work.. upgrade the firmware to 1.0 release 12.. see if that would fix your difficulty..

 

[buddha2]

Hello, if you have Yahoo Messenger installed on any of your PCs it can cause this to happen, EVEN IF you have disabled UPnP on the router! As soon as Yahoo Messenger runs, it makes the router point port 80 to whatever PC it is running on. Once again, it doesn't matter if you disable UPnP on the router. Apparently the router firmware has a bug which results in UPnP always being enabled. (I had this exact same problem when trying to run a Linux web server along with a desktop on the same network. I fixed the problem simply by uninstalling Yahoo Messenger, then rebooting the PCs and the routers. After that everything has worked fine!)