Hi all!
I am experiencing a multicast packet loss on batman-adv mesh, this can appear normal but it is not because the mesh is on top of wired Ethernet link!
the host fe80::c8e0:2cff:fe9b:6d1f is sending a multicast hello message every 4 seconds on bat0 interface, but as you can see from the dump timing on a machine attached on the same switch they are not arriving regurarly so what is happening? Is this normal?
here is the dump
eigenServer ~ # tcpdump -n -i bat0 udp port 6696 and host fe80::c8e0:2cff:fe9b:6d1f [4/323] tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on bat0, link-type EN10MB (Ethernet), capture size 96 bytes 14:45:19.295707 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 151 14:45:40.133468 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:45:53.357606 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:46:01.118909 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:46:01.227914 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 79 14:46:03.210770 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 79 14:46:04.161707 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:46:04.308875 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 79 14:46:09.058416 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:46:21.473697 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 53 14:47:12.359258 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:47:13.063186 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:47:14.094512 IP6 fe80::488e:c5ff:fee9:8901.6696 > fe80::c8e0:2cff:fe9b:6d1f.6696: UDP, length 24 14:47:14.115996 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > fe80::488e:c5ff:fee9:8901.6696: UDP, length 40 14:47:18.288823 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:47:24.098438 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:47:31.905127 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 151 14:47:36.944597 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:47:51.131644 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 60 14:48:11.621499 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 151 14:48:24.418458 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76 14:48:27.608263 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 151 14:48:30.003085 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 20 14:48:31.567988 IP6 fe80::c8e0:2cff:fe9b:6d1f.6696 > ff02::1:6.6696: UDP, length 76
batman version is the same on both host eigenServer ~ # batctl -v batctl gentoo-2012.2.0 [batman-adv: 2012.2.0]
thanks for help!
On Mon, Aug 06, 2012 at 03:05:49PM +0200, Gioacchino Mazzurco wrote:
Hi all!
I am experiencing a multicast packet loss on batman-adv mesh, this can appear normal but it is not because the mesh is on top of wired Ethernet link!
the host fe80::c8e0:2cff:fe9b:6d1f is sending a multicast hello message every 4 seconds on bat0 interface, but as you can see from the dump timing on a machine attached on the same switch they are not arriving regurarly so what is happening? Is this normal?
Hello Gioacchino,
I'd say that losing packets is not normal :-) Have you tried to use batctl td on the wired interface? You should see the "broadcast" packets going around. It would be interesting to understand if on batctl you had more packets than what you are receiving on the node.
Cheers,
p.s. what kind of hello messages are they? Their size is changing over time..
The problem was that babeld assumed bat0 as a wired interface so when 2 or 3 packet was lost it marked the route as unreachable, now the problem is fixed thanks to a patch from julius
by the way it is not normal that batman loss packet on wired links and I think we should do some debug to understand what is happening...
I am going to do some test as ordex said trying to make things clear
On 08/06/2012 03:43 PM, Antonio Quartulli wrote:
On Mon, Aug 06, 2012 at 03:05:49PM +0200, Gioacchino Mazzurco wrote:
Hi all!
I am experiencing a multicast packet loss on batman-adv mesh, this can appear normal but it is not because the mesh is on top of wired Ethernet link!
the host fe80::c8e0:2cff:fe9b:6d1f is sending a multicast hello message every 4 seconds on bat0 interface, but as you can see from the dump timing on a machine attached on the same switch they are not arriving regurarly so what is happening? Is this normal?
Hello Gioacchino,
I'd say that losing packets is not normal :-) Have you tried to use batctl td on the wired interface? You should see the "broadcast" packets going around. It would be interesting to understand if on batctl you had more packets than what you are receiving on the node.
Cheers,
p.s. what kind of hello messages are they? Their size is changing over time..
b.a.t.m.a.n@lists.open-mesh.org
-
Antonio Quartulli -
Gioacchino Mazzurco