This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-bugs] [Bug 1085] New: Multicast corruption


           Summary: Multicast corruption
           Product: Xen
           Version: 3.0.3
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: critical
          Priority: P2
         Component: Unspecified
        AssignedTo: xen-bugs@xxxxxxxxxxxxxxxxxxx
        ReportedBy: erwan@xxxxxxxxxxxx

Hello all,

In my DomU, I've been experiencing some network corruption using some
UDP multicast packets.
Take two DomU on two different hosts and generates some multicast
traffic using mgen (http://cs.itd.nrl.navy.mil/work/mgen/index.php)
This tool is able to check integrity using the "check" option. I've been
running that tool for hours without any errors.

Then, just generate some unicast traffic between the same hosts using
netpipe (http://www.scl.ameslab.gov/netpipe/).
Once netpipe generates some packets bigger than 256K, mgen reports some

I've been doing more tests, here come the results:
- if the two domU are on the same host this bug doesn't occur
- if I use mgen to generates some unicast UDP packets between the two
domU instead of multicast, this problem doesn't occur
- if I do the same scenario using some dom0 instead of the domU, this
problem doesn't occur

I would like to know if some experienced that and have any idea on how
it could be fixed in Xen or if I am doing something wrong ?

DomU: FC6, 2.6.20-1.2952.fc6xen

Dom0: FC6, 2.6.20-1.2952.fc6xen
   net driver: tg3

Hardware: x86_64 hosts with 1G of ram
Each domU have 256M of ram

NPtcp (netpipe client) used to this test is available at :

mgen used for this test is available at :

Command used on the first domU to generate the mcast traffic for 30mn:
./mgen check event "0.0 ON 0 UDP SRC 30788 TXBUFFER 2000 DST POISSON [100 300] INTERFACE eth0" check event "1800.0
OFF 0"

Command used on the other domU to receive the mcast traffic for 30mn:
./mgen check event "LISTEN UDP 30788" event "0.0 JOIN PORT
30788 INTERFACE eth0" event "1800.0 LEAVE" log "test.log"
mgen will show on the console if some checksum error occurs

Command used to receive the netpipe traffic on the second domU:

Command used to generate the netpipe traffic of the first domU:
./NPtcp -h <host_ip_of_the_other_domU>

Configure bugmail: 
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

Xen-bugs mailing list

<Prev in Thread] Current Thread [Next in Thread>