Http simply stops serving pages

Domino intermittently stops serving iNotes/http on a secondary NIC. After disabling/enabling the card again and restarting http task, it will come back online and work for hours before dropping again.

-The network card never drops pings during the outage

-We’ve swapped to a different card/different model

-Changed port speeds (gb/full vs Auto)

-It’s not DNS/name resolution related because it’s unavailable on the direct IP too.

-Windows event logs are perfectly clear

-Domino console log is clear

-HTTP task never stops

It will be working one second, then simply stop responding the next, even though all components are online. It’s like Domino stops seeing the card as an available path.

Thoughts?

More background:

New HP DL380, Win2003R2-64bit, Domino 8.5 64bit (single server), all newest drivers