Hi, I've found that dom0 <-> domU begin loss ~ 20% packets on high UDP traffic (with bridged virtual network setup). The fix is to increase txqueuelen on vif* interfaces which is very low (32) by default. Tested with Centos 6.5, 3.10.23-11.el6.centos.alt.x86_64 xen-4.2.3-26.el6.centos.alt P.S. This problem widely discussed in the internet, but nobody publish this fix (why?) http://serverfault.com/questions/442674/xen-pv-packet-loss http://lists.xen.org/archives/html/xen-users/2009-01/msg00381.html ... -------------- next part -------------- A non-text attachment was scrubbed... Name: xen-vif-txqueuelen.patch Type: text/x-patch Size: 508 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20131215/193f48ad/attachment-0005.bin>