The ignore-client-uids option is supposed to make it easier to handle PXE-boot clients that would like the same IP address to be allocated to them during both boot phases, the first boot not providing a client uid (therefore being assigned a lease based solely on MAC address) and the second sending a client uid, and therefore being 'seen' as a new client.

At present this mostly works, but there is (at least) one corner case: in a load-balancing situation, and where the lease initially granted has expired, the client DISCOVER might be load-balanced to the other failover peer because of 'on the fly' load balancing based on hashing the client identifier (mac or uid as appropriate), and thus still be given a different address.

This can introduce some instability into the dual-boot IP address assignments.  It would be better if, when 'ignore-client-uids' has been specified, that the hashing for load-balancing purposes also ignores client uids.

(There may also be other locations in DHCP logic that could also benefit from this setting being observed but which haven't yet been identified).