Cannot access web server remotely

I'm having a problem with an internal web server which we host our intranet on which i'm attempting to connect to using a hostname from dyndns.com (FYI the server is not accessible via IP either). We can access the site the web server is running on internally but not remotely. As far as i can tell there is no issue with port forwarding as i can remotely connect to a web server on my windows machine without any issues through the same router. The intranet server is on an old linux box running Mandrake, here are the details:

cat /proc/version
> Linux version 2.6.8.1-12mdk (quintela@n5.mandrakesoft.com) (gcc version 3.4.1 (Mandrakelinux (Alpha 3.4.1-3mdk)) #1 Fri Oct 1 12:53:41 CEST 2004

Its not possible to update the OS so I need to get this working with this setup. As far as i can tell iptables is not even setup so i don think this is the issue. Not sure where to check for connection errors etc tho. I believe this may have been set up previously using a webmin install if that helps in any way.

If you need any more details then please ask.

Thanks.

From serverfault seengee

• Does the webserver have different hostnames for internal/external access? If so, make sure it's configured to answer requests with either one; name-based virtual hosting can present this sort of issue, as can any URL-modifying modules like mod_rewrite. Apologies if this next solution is obvious, but is there a firewall configured on the server as well? There may be a rule that allows requests from your LAN, but not the big bad Internet.

  seengee : to be honest i'm not sure where to check either of these things, can you advise on this? thanks

  RainyRat : Since your clients aren't making it as far as Apache, you don't need to bother about the first part (yet). As for the firewall, I believe it's set up through the Mandrake Control Centre. I haven't actually used it, so I can't give you specifics.

  seengee : web server currently locked away so no GUI access at the moment so will have to try and do this on command line, googling this now

  RainyRat : Google tells me that the CLI version of control centre is (a) called "drakconf", and (b) may not be installed by default.

  seengee : drakconf is installed but when i select the firewall option then it just dumps me back to the command line, other options such as services allow me to adjust values so not sure what is wrong here.

  seengee : i've found webmin access for this server, not sure if there will be something in there to help .. ??
  From RainyRat

• Take a step back. Can you access the server by IP address? If you can you need to ensure the dyndns host name is being correctly resolved. If the IP address is dynamic you may be trying to access the server with a cached address, which may be incorrect.

  seengee : hi, sorry but i think the dyndns mention has probably confused things. the server is not remotely accessible by IP either.
  From John Gardeniers

• Some ISPs block any incoming transmission on port 80 (one such example would be Videotron in Canada). Try listening on an other port such as 8002 (above 1024, not 8080) and see if you can connect.

  seengee : I am able to connect to an apache web server on my local windows machine though. however, as soon as i change the IP to forward port 80 traffic to the linux server thats when the page refuses to load and nothing reaches apache
  From Andrew Moore

• inside webmin > networking > network configuration > network interfaces for some reason the default route had the wrong IP for our router. I changed this to the correct IP and it all works. Thanks for all the help.

  From seengee