6.0 ethernet problem with 4GB ram

[Erik Stian Tefre]

Hi list!

I'm seeing a strange network problem on a couple of athlon 64 X2 boxes
with 4 GB ram. The ethernet interfaces (em in one box and vge in the
other) stops working if I enable more than 2 GB of ram. The interfaces
continue to receive incoming broadcast packets (verified with tcpdump)
but nothing else seems to work (the local arp table stays empty).  

The ethernet interfaces work OK on:
-6.0 i386 GENERIC (without PAE) 
-6.0 amd64 GENERIC with hw.physmem=2g set in loader

They don't work on:
-6.0 i386 PAE
-6.0 amd64 GENERIC

I have tested this on 6.0 release. Upgrading to RELENG_6 (cvsuped today)
seems to make no difference. Compiling the kernel with or without SMP
also makes no difference.

Anyone have any ideas or workarounds other than limiting the memory to
2GB?

--
Erik Stian Tefre