Arvin, Thanks a lot for pointing tcpdump. What I have observe is that the packets which seems to be dropped are STP related [root@network ~]# tcpdump -i eth0 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 23:15:37.967118 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:39.967163 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:41.967121 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:43.967147 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:45.967118 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:47.967156 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:49.967131 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:51.967132 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:53.967195 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:55.967138 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 23:15:57.967165 STP 802.1d, Config, Flags [none], bridge-id 8000.52:54:00:e4:ec:1b.8003, length 35 Now, my main issue is that I observe those packets also in the disabled virtio-net driver (with driver name=qemu), but in that case, no packets are dropped So is that a different behaviour of the bvirtio-net when it is in Kernel mode and when it is in User space ? Patrick > On 26 Jan 2016, at 20:51, Troels Arvin <troels@xxxxxxxx> wrote: > > pichon wrote: > > Hello, > > pichon wrote: >> On each of my guests VM, I see constantly a RX dropped number increasing >> , Even if the VM does nothing ! > > I'm seeing the same phenomenon on one of our LANs (on another LAN, I > don't see it). My setup is with RHEL 7, and it is seen on both physical > and virtual servers. I don't see it on any RHEL 5 or 6 servers. > > A strange observation: If I start tcpdump, the package drops stop. > (Setting the NIC in promisc mode does not have any impact; it has to be > tcpdump.) > > I suspect that it has to do with this: > https://www.netiq.com/support/kb/doc.php?id=7007165 > If this is the case, it's simply because recent kernels classify packets, > and then there's nothing to worry about. > > - But Red Hat Support does not share that view. I have an open case with > Red Hat Support about it; lots of stuff has been tried, but we have yet > to reach a conclusion. > > -- > Troels > > > _______________________________________________ > libvirt-users mailing list > libvirt-users@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvirt-users > _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
