Comment 5 for bug 1400217

The uploaded patch will address that as well.

It's again caused by the fact that it was inspecting the interface for addresses to decide what to add.

When "l3_agent" is restarted on the master it does not get any floating_ip's configured because they're already "configured" according to the interface, meaning failover will leave them behind.
When a vip is added/removed on a standby it gets multiples due to inspecting the interface and none being "configured", so neutron add's them all.

For this reason I don't think the right answer is to override what is there but check what is configured from the definitive source, the keepalived config.

If we want to do verification at "add_vip" we should make it check if the new IP is a duplicate and if it is, then throw an error or debug message, then return without adding the address. A duplicate address should never reach "add_vip".