On Linux for s/390: Load Balancer issues a gratuitous ARP to move IP addresses from one Load Balancer to another. This mechanism is therefore tied to the underlying network type. When running Linux for s/390, Load Balancer can natively do high availability takeovers, complete with IP address moves, only on those interfaces which can issue a gratuitous ARP and configure the address on the local interface. This mechanism will not work properly on point-to-point interfaces such as IUCV and CTC and will not work properly in certain configurations of qeth/QDIO.