Hi, I''m trying to understand how (i.e. which event triggers what) a gratuitous ARP is supposed to be sent in case of live migration ... The only path I found that would create a NOTIFY_PEER is in the netfront driver if the state is changed to ''Connected''. Is that the path supposed to be triggered by a live migration ? Cheers, Sylvain
On Tue, 2013-03-12 at 16:41 +0000, Sylvain Munaut wrote:> Hi, > > I''m trying to understand how (i.e. which event triggers what) a > gratuitous ARP is supposed to be sent in case of live migration ... > > The only path I found that would create a NOTIFY_PEER is in the > netfront driver if the state is changed to ''Connected''. Is that the > path supposed to be triggered by a live migration ?Yes, because devices are reconnected after the migration, which triggers that path. Ian.
Hi,> Yes, because devices are reconnected after the migration, which triggers > that path.Thanks. I''ve now confirmed the gratuitous ARP is properly sent. I can see it in a tcpdump on the VM itself, and using tcpdump -i any on the dom0. However I never see it on the network itself, nor on the dom0 on the bridge interface. So either something is blocking it somewhere (bridge code or iptables), it it''s sent before the VIF is attached to the bridge. Cheers, Sylvain