Re: VLAN and bridging with xen - WORKAROUND

On Wed, 23 Nov 2005 23:17:15 +1300
Greg Brackley <[email protected]> wrote:

> ----- Original Message ----- 
> From: "Ben Greear" <[email protected]>
> > Or, it could be a checksum support issue or similar.
> >
> > You probably should cross-post this with the bridging and/or xen mailing
> > lists...or just send to [email protected]
> > (I think this is probably more a Xen/Bridging problem than VLANs, though
> > it's possible there is a nasty interaction between all three.)
> 
> I have found that by disabling TX CHECKSUM OFFLOAD on the veth0/eth0 
> (domain0/domainU) xen interface the symptom goes away.  There is still an 
> issue with the checksum offload support, but I think have a feasible 
> workaround for now (I still want to do a bit more testing). Thank you to 
> everyone that provided assistance.
> 

Makes sense because the sk98lin driver does checksumming incorrectly.
Thes code in sk98lin/skge.c:XmitFrame assumes that the checksum offset
is ipheader + tcp header, so it doesn't take into account VLAN.
This is bogus, since it is an out of tree driver, you need to tell 
SysKonnect. The skge and sky2 drivers do it right.