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Old 07-09-2014, 12:29 PM   #1
suicidaleggroll
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port forwarding stopped working


Yesterday morning everything was working great. Yesterday noonish we had a long power failure, after about 15 minutes I shut down all of the machines and waited. Two hours later power came back on, I turned the machines and networking equipment back on, and that's when the problem started.

There are 5 servers that have ports forwarded to them by the router. Three came up fine, two didn't, call them box7 and box8.

Box8 just has ssh forwarded to it on a unique port. Box7 has ssh, ftp, and http forwarded to it. All machines and all services are working fine from inside the network (whether I go direct to the machine's internal IP, or if I go to the router's public IP and allow it to forward the connection, either works fine), but nothing from outside the network is making it to box7 or 8 (ssh, ftp, http all fail).

If I change the router to point box8's ssh port to another working machine, it works fine. If I change the router to point another working machine's ssh port to box8, it fails. So the router and external firewall seem to be fine and are allowing the connections through, the problem appears to be isolated to these two machines. And since I can use the router's public IP from within the network and the connection gets forwarded correctly and makes it through, it seems the router is happy with the machine, it's IP, and the port forwarding settings.

Box7 and 8's firewalls have been disabled for testing, no difference. There are no messages logged in /var/log/messages or /var/log/secure. It's as if the packet just disappears between the router and the machine for external connections.

Both boxes are running Fedora, have been working fine for many years, and no configuration changes have been made recently.

Any ideas?



Note: I experienced a very similar problem several years ago on a different machine, posted here:
http://www.linuxquestions.org/questi...ns-4175417888/

Unfortunately rebooting the machines has made no difference in this case.

Last edited by suicidaleggroll; 07-09-2014 at 12:32 PM.
 
Old 07-09-2014, 02:06 PM   #2
suicidaleggroll
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FIXED

For some reason on these two machines the default network interface changed when they restarted. The default switched from the primary 1GbE LAN to the small 10GbE LAN that's used for high speed comms between servers. And for some reason, this switch caused the machine to ignore/reject/fail on incoming connections, but only those connections that originated from outside the network...weird.
 
  


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