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(a)arvin.dk>
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(a)redhat.com
https://www.redhat.com/mailman/listinfo/libvirt-users