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Re: [Xen-users] unstable network problem

On Monday 08 August 2005 15:34, Tim Durack wrote:
> I must be doing something wrong:
> Have set up a basic Xen system, Dom0 + one Xen0 guest. Configured for
> a routed network.
> Ping Dom0 -> guest works.
> Ping guest -> Dom0 works.
> nmap Dom0 -> guest reports port 22 open.
> Ssh Dom0 -> guest hangs.
> ssh guest -> Dom0 hangs. Same behaviour. Watching a packet capture
> shows traffic passing but with retransmits and poor performance.
> If I build a gre tunnel between Dom0 and guest, everything works fine,
> with the exception that I must generate some traffic from the guest
> first.
> I have no iptables rules configured, so it's not that. Looks like
> there is maybe some issue with tcp traffic between domains.
> Looks like a bug to me, but I'm posting to the user list first.

There was a long thread about this problem maybe one or two weeks ago...
I think the problem was that the virtual eth devices had packet queueing 
disabled (txqueuelen:0 on ifconfig), and had a 4k size max. ring buffer for 
transfering packets between domains.
Whenever that buffer would run full, packets are dropped...


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