I changed my old 10/100 NIC Card by a new one, normally handled by the « re » driver : a D-link Gigabit DGE-528T (chipset : Realtek 8269S).
Thus, starting to see bunch of ‘re0: watchdog timeout’ in my log, and impossibility to ping anyhing.
After googling and changin some options (‘ifconfig -tso’), repluging the card, the solution was to remove the (unused) PCI card next to the NIC.
IRQ conflict ?
Hope it helps 🙂