re0: watchdog timeout

[Frank Volf]

Hello,

I'm experiencing watchdog timeouts with my Realtek interface card.

I'm using a fairly new system (Shuttle DS47), running FreeBSD 10-STABLE.
For this shuttle a patch has been recently committed to SVN to make this 
card work at all (revision *262391* 
<http://svnweb.freebsd.org/base?view=revision&revision=262391>).

The timeout is only experienced under heavy network load (the system is 
running a bacula backup server that backups to NFS connected storage), 
and typically large full backups trigger this. Normal traffic works fine 
(this system is e.g. also my firewall to the Internet).

What might not be standard is that I use sub-interfaces on this system.
First of all, the only way that I can get the sub-interfaces to work at 
all is by using

         ifconfig_re0="-vlanhwtag"

I'm not sure that is related.

The question is how can we debug this to solve the problem?
I have non clue, but I'm happy to assist if somebody can tell me what I 
should do.

Some information that might be useful:

root at drawbridge:/usr/local/etc/bacula # dmesg | grep re0
re0: <RealTek 8168/8111 B/C/CP/D/DP/E/F/G PCIe Gigabit Ethernet> port 
0xd000-0xd0ff mem 0xf7a00000-0xf7a00fff,0xf0100000-0xf0103fff irq 17 at 
device 0.0 on pci2
re0: Using 1 MSI-X message
re0: ASPM disabled
re0: Chip rev. 0x4c000000
re0: MAC rev. 0x00000000
miibus0: <MII bus> on re0
re0: Ethernet address: 80:ee:73:77:e9:ab
re0: watchdog timeout
re0: link state changed to DOWN
re0.98: link state changed to DOWN
re0.10: link state changed to DOWN
re0.11: link state changed to DOWN
re0.12: link state changed to DOWN
re0: link state changed to UP
re0.98: link state changed to UP
re0.10: link state changed to UP
re0.11: link state changed to UP
re0.12: link state changed to UP
...

root at drawbridge:/usr/local/etc/bacula # uname -a
FreeBSD drawbridge.internal.deze.org 10.0-STABLE FreeBSD 10.0-STABLE #0 
r262433: Mon Feb 24 16:25:35 CET 2014 
root at drawbridge-new.internal.deze.org:/usr/obj/usr/sources/src10-stable/sys/SHUTTLE 
i386

root at drawbridge:/usr/local/etc/bacula # pciconf -lv re0
re0 at pci0:2:0:0: class=0x020000 card=0x40181297 chip=0x816810ec rev=0x0c 
hdr=0x00
     vendor     = 'Realtek Semiconductor Co., Ltd.'
     device     = 'RTL8111/8168B PCI Express Gigabit Ethernet controller'
     class      = network
     subclass   = ethernet


Kind regards,

Frank