Network stalling

Network stalling

[Tim Durack]

[-- Attachment #1.1: Type: text/plain, Size: 1377 bytes --]

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:>

[-- Attachment #1.2: Type: text/html, Size: 1437 bytes --]

[-- Attachment #2: Type: text/plain, Size: 137 bytes --]

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Re: [Xen-users] Network stalling

[Nivedita Singhvi]

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

Re: Network stalling

[Tim Durack]

[-- Attachment #1.1: Type: text/plain, Size: 525 bytes --]

> 
> 
> 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.


Okay, good to know. I hadn't seen any acknowledgement that routing was 
broken.

I'll stick to my gre tunnels for now.

Tim:>

[-- Attachment #1.2: Type: text/html, Size: 718 bytes --]

[-- Attachment #2: Type: text/plain, Size: 137 bytes --]

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Re: Network stalling

[Tim Durack]

[-- Attachment #1.1: Type: text/plain, Size: 2320 bytes --]

Do you mean the network scripts are broken, or the handling of interfaces in 
Dom0 is causing issues with a routed setup?

I'm configuring everything manually. The fact that I have to build gre 
tunnels to make things work as expected suggests their is something broken 
in the netfront/netback code to me.

Tim:>

On 8/31/05, Nivedita Singhvi <niv@us.ibm.com> wrote:
> 
> 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
>

[-- Attachment #1.2: Type: text/html, Size: 2661 bytes --]

[-- Attachment #2: Type: text/plain, Size: 137 bytes --]

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users