No network after upgrade

[Martti Kuparinen <martti.kuparinen%iki.fi@localhost>]

Hi,

I just upgraded our NetBSD/xen host to the latest 4.0_STABLE (including 
xen.gz and both dom0 and domU kernels) and I can't access the network 
anymore. It looks like the ARP reply packets are no longer going through 
and this of course makes the whole network unreachable. Note that the 
ARP request are coming into my domU host just fine according to tcpdump, 
it's just the reply which is not reaching the other host.

The physical interface on my dom0 is

wm1 at pci3 dev 2 function 0: Intel i82541GI 1000BASE-T Ethernet, rev. 0
wm1: interrupting at ioapic0 pin 21, event channel 7
wm1: 32-bit 33MHz PCI bus
wm1: 64 word (6 address bits) MicroWire EEPROM
wm1: Ethernet address 00:11:43:ce:66:f5
igphy1 at wm1 phy 1: Intel IGP01E1000 Gigabit PHY, rev. 0

and I have multiple VLANs on top of that, as an example

# cat /etc/ifconfig.vlan1128
create
vlan 1128 vlanif wm1
!ifconfig bridge1128 create
!brconfig bridge1128 add vlan1128 up

Any ideas what might be wrong? I'll try to downgrade (2008-09-24) and 
see if it helps...

p130 = real host
p137 = NetBSD/xen domU 4.0_STABLE

(ping p137 from p130)

ROOT p130:~> tcpdump -n arp
22:46:20.391032 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130
22:46:21.404465 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130
22:46:22.408540 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130

ROOT p137:~> tcpdump -ni xennet0 arp
22:46:19.846647 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130
22:46:19.846667 arp reply xxx.xxx.xxx.137 is-at 00:16:3e:01:37:01
22:46:20.860020 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130
22:46:20.860033 arp reply xxx.xxx.xxx.137 is-at 00:16:3e:01:37:01
22:46:21.864123 arp who-has xxx.xxx.xxx.137 tell xxx.xxx.xxx.130
22:46:21.864135 arp reply xxx.xxx.xxx.137 is-at 00:16:3e:01:37:01