FreeBSD 7.3, reboot after panic: double fault

[c0re]

And some more workaround:

On 7.2

ifconfig mtu
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> metric 0 mtu 1280

Apache running on em0 alias address.

>From remote machine trying to download 10Kb file and looking into tcpdump.
No kernel panic. But 7.2 dows not respond to GET request, but in apache
access log I see that it responds with OK, and there no tcp push packets
from 7.2. So file not downloading. But at least no kernel panic :)
Then I setup 1200 mtu on em0 and everything is okay, file download
successful.

On 7.3 same mtu 1500 adn 1280 - kernel panic when trying to download file.
When I configure on em0 mtu 1200 - no kernel panic and file download
successful.

So it looks like mtu discovery related kernel panic.

Hope this will help to resolve problem.

Cheers.