So, my server is redking. I've got a unique setup with two network cards so I can have protected access to it from the internal network, but all other traffic comes from the outside. As a result, configuring it has been a bit tricky. It also didn't help that the integrated NIC was acting spazzy recently.
Anyway, it looks like my issue was one of routes, although I can't figure out why. I'm guessing it has something to do with how it keeps the IP address.
So, if you hit my site from, say, 234.1.4.8, then when it tries to send a packet out, it's going to look at the routing table to see where to send it. If the routing table has entries for:
LAN (192.168.1.*)
WAN (254.16.1.*)
Then your address won't match either of these. That's what the default gateway is for (from what I gather). It's the "I don't know where this should go, send it here" interface.
So it looks like what was happening was that the WAN gateway was being brought up first, and the LAN second, which then had the LAN's gateway being default. And through that, traffic can't get out, apparently. Maybe. It still doesn't make sense, as the logs for the services (mail, web, etc) don't show ANY traffic reaching them. If it was really an outbound problem, I'd figure you'd see the entries in the logs, but he traffic wouldn't get there.
All I know is that changing the gateway in the routing table seems to have fixed it. Now to figure out why...
Posted by flynn at June 19, 2007 11:24 AM