a related problem is having N ip addrs bound to M nics on a host, where N > M.
if an ssl connection fails and debug is needed between the M:N:host and some other ssl-speaking box, then it makes a difference if the ssl connection is associated with the primary, or some aliased (set N-1) ip addr. client failure semantics are primary address specific, for some value of ssl clients. in theory you could alias an ns box's ip addrs (just did that, renumbering), and have multi-addrs on a server authoritative for multi-zones, and not have a flag day. have fun, jobs are scarce as hen's teeth.