Re: [Xen-users] Network stalling

[Nivedita Singhvi <niv@us.ibm.com>]

Tim Durack wrote:
> Guess I should add my experiences:
> 
> Running unstable (approx. two weeks old now.)
> 
> Dom0 vif1.0 -> guest eth0: icmp works, ssh fails, tcp seems to have checksum 
> issues. Building gre tunnels over this works around the problem. I thought 
> maybe this was device driver related (tg3), so I tried bcm5700 with the same 
> result.

> Tried a similar setup with a machine with e100 driver. This time I get udp 
> checksum errors instead of tcp, so dns fails but ssh works ;-( A gre tunnel 
> is my current workaround.
> 
> I say checksum issues because ethereal is complaining about transport layer 
> checksums when I do a capture to diagnose the problem.
> 
> Tried various combinations of disabling tx/rx/sg/to with ethtool in both 
> Dom0 and guest, to no avail. Also tried hacking the driver code to 
> permanently disable offloads. Tried looking for the difference between 
> stable/unstable netfront and netback, but didnt get far.
> 
> A bridged setup works, ip address on Dom0 veth0, Dom0 vif0.0 bridged with 
> Dom0 vif1.0. Real pain in the neck to firewall though, due to all the 
> interfaces. Never managed to get Masquerading to work in this setup, so went 
> back to a routed network with gre tunnels...
> 
> I can try a more recent unstable if it might help, but I haven't seen any 
> evidence of anything having fixed this. Love to have a simple routed setup 
> working.

Tim, it's very likely that your initial problem has been resolved
in unstable - Ian, Keir, et. al have put in quite a few fixes which
have closed most of the outstanding issues we had. I think there
are only a few remaining issues. However, currently routing is
broken in unstable, so you might want to hold off on testing current
unstable until that gets fixed.

thanks,
Nivedita