I have two machines behind my NAT router. I've had the same setup for years. 192.168.2.1 is my router; 192.168.2.2 is my wife's machine, which runs my webserver; 192.168.2.3 is my machine, has my poker stuff, postgres DB, etc. I've had port forwarding for various things point to each device with no problem. You all should be able to access http://ddubois.bounceme.net/ ; I've had that redirection service pointing to my subnet for years, with port forwarding doing it's job, but if you tried it now, your browser wouldn't connect (my PocketPc can't anyway).

About a month or two ago I noticed I couldn't connect to the web server, but didn't have a chance to look at it. Well, now I'm looking. And I cannot connect to neither the apache web server nor the ftp server running on my wife's machine. I can ping it, and I can share windows file systems between the two machines(!!), but "telnet 192.168.2.2 80" and "ftp 192.168.2.2" both time out. Using two different softwares would seem to indicate it's not a web server configuration problem.

If I open network settings, the machine reports it is 192.168.2.2 (assigned, not DHCP). If I try to administer my router from both locations, first my wife's, then mine, the router will complain its already being administered by 192.168.2.2. If I try to "telnet 192.168.2.2 80" and "ftp 192.168.2.2" from that machine directly, it connect/works fine. So the machine thinks its .2, and the router thinks it's .2. This indicates it's probably not a mistaken identity problem.

Wtf?

If you can connect locally but not from another computer, that sounds like a firewall blocking it. Is apache running on linux or windows? Maybe check the windows firewall on your wife's machine if it's windows. Also, try running arp -a from the command prompt of 192.168.1.3 to make sure it's matching 192.168.1.2 to the mac address of your wife's computer. If not, it could be a duplicate IP. When you telnet to 192.168.1.2 from 192.168.1.3, does it time out quickly or does it take 10-15 seconds?

The timeout takes awhile. I'll try arp when I get home, thanks for the tip. And now that you mention it, the software firewall explanation sounds extremely likely. My 5 year old will spend hours, if you let him, clicking on anything and everything; he could easily have turned on the software firewall. I'll check that when I get home too.

If it takes a while, this also can indicate a firewall (or the host being down completely). If the host is up and receives a connection request to a closed port, it will respond back to close the connection. However, if a firewall is in place to block the connection, it will simply ignore an incoming request and not respond back (depending on how the firewall is configured). It will appear to the remote host as if it doesn't exist at all. This will cause the connection attempt to take longer because it waits until the connection request times out before it fails.