Hi Joe, strange thing but after setting multicast_router once to 2, ipv6 worked on all vnet devices. I also restarted the node and the vms and it is still working. Seems like this fixes the problem.... Thanks for you help! David Am 20.09.2012 01:39, schrieb Joe Pruett: > On 09/19/2012 04:29 PM, Joe Pruett wrote: >> On 09/14/2012 03:16 PM, David Hackl wrote: >>> IPv6 is enabled. As I said, it works good on the node itself. I can ping >>> it and also ping out of it. >>> >> this is a really annoying bug in the linux bridge code. ipv6 neighbor >> discovery relies on multicast, and the bridge code tries to optimize >> multicast by not treating it as broadcast. but since v6 neighbor >> discovery doesn't use v4 igmp, the bridge code never realizes what >> bridge interfaces should get what multicast packets. the easiest fix is: >> >> echo 2 > /sys/class/net/vif#.#/brport/multicast_router >> >> with the appropriate #.# substituted (or just do them all), which tells >> the bridge code that there is a multicast router on that port and >> therefore it should receive all multicast traffic. i ran into this a few >> months back and had forgotten it again until now. i never found a way to >> make it happen at boot time, or via some script in xen, but i will now >> dive into that hunt again... >> > ah, the memory is going. i did come up with a hacked way to make this > happen for xen vms, so you'd have to find another way to make it happen > for kvm. for xen, there is a script that is called to create the vif > interface, and i just hacked in the echo in there. i had to do it as a > background job with a 5 second delay to get around some timing issue. > and it only works for newly created vms, once a vm has been created, it > remembers the original script name, so suspending and resuming gets you > back to square one, even rebooting from within the guest. > > here is the code that was added to the vif-bridge script, just to see > how easy it was: > > (sleep 5 ; echo 2 > /sys/class/net/$vif/brport/multicast_router) & > > _______________________________________________ > CentOS-virt mailing list > CentOS-virt@xxxxxxxxxx > http://lists.centos.org/mailman/listinfo/centos-virt _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos-virt
