em0 and em1 watchdog timed out

[Frank de Bot (lists)]

On a server I have 2 interfaces configured in a lagg. It seemed to be
running stable until now (about a week), both interfaces repeatable go
down after a watchdog timeout.

Output from /var/log/messages

Oct  2 10:15:11 nas kernel: em0: Watchdog timeout Queue[0]-- resetting
Oct  2 10:15:11 nas kernel: Interface is RUNNING and ACTIVE
Oct  2 10:15:11 nas kernel: em0: TX Queue 0 ------
Oct  2 10:15:11 nas kernel: em0: hw tdh = 804, hw tdt = 905
Oct  2 10:15:11 nas kernel: em0: Tx Queue Status = -2147483648
Oct  2 10:15:11 nas kernel: em0: TX descriptors avail = 915
Oct  2 10:15:11 nas kernel: em0: Tx Descriptors avail failure = 0
Oct  2 10:15:11 nas kernel: em0: RX Queue 0 ------
Oct  2 10:15:11 nas kernel: em0: hw rdh = 912, hw rdt = 911
Oct  2 10:15:11 nas kernel: em0: RX discarded packets = 0
Oct  2 10:15:11 nas kernel: em0: RX Next to Check = 912
Oct  2 10:15:11 nas kernel: em0: RX Next to Refresh = 911
Oct  2 10:15:11 nas kernel: em0: link state changed to DOWN
Oct  2 10:15:13 nas kernel: em0: link state changed to UP
Oct  2 10:15:13 nas devd: Executing '/etc/rc.d/dhclient quietstart em0'
Oct  2 10:21:56 nas kernel: em1: Interface stopped DISTRIBUTING,
possible flapping
Oct  2 10:21:59 nas kernel: em1: Watchdog timeout Queue[0]-- resetting
Oct  2 10:21:59 nas kernel: Interface is RUNNING and ACTIVE
Oct  2 10:21:59 nas kernel: em1: TX Queue 0 ------
Oct  2 10:21:59 nas kernel: em1: hw tdh = 686, hw tdt = 806
Oct  2 10:21:59 nas kernel: em1: Tx Queue Status = -2147483648
Oct  2 10:21:59 nas kernel: em1: TX descriptors avail = 896
Oct  2 10:21:59 nas kernel: em1: Tx Descriptors avail failure = 0
Oct  2 10:21:59 nas kernel: em1: RX Queue 0 ------
Oct  2 10:21:59 nas kernel: em1: hw rdh = 167, hw rdt = 166
Oct  2 10:21:59 nas kernel: em1: RX discarded packets = 0
Oct  2 10:21:59 nas kernel: em1: RX Next to Check = 167
Oct  2 10:21:59 nas kernel: em1: RX Next to Refresh = 166
Oct  2 10:21:59 nas kernel: em1: link state changed to DOWN
Oct  2 10:22:02 nas kernel: em1: link state changed to UP
Oct  2 10:22:02 nas devd: Executing '/etc/rc.d/dhclient quietstart em1'

it seems to occur when the interface are loaded. On the same server I
also have a PCI card, the same issue occurs here. em0 and em1 are both
onboard 80003ES2LAN. the PCI card is 82571EB.

I've found different threads, but I couldn't manage to find  a fix for this.

What else can be wrong?

Regards,

Frank de Bot