Configuring the net.slp.interfaces property enables a DA on the multihomed host to bridge service advertisements between the subnets. Such configuration is useful if multicast routing is turned off in the network, but unicast routing between interfaces on a multihomed host is enabled. Because unicast is routed between the interfaces, hosts on a subnet different from the subnet on which the service is located can contact the service when they receive the service URL. Without the DA, SA servers on a particular subnet receive only broadcasts that were made on the same subnet, so they cannot locate services off of their subnet.
The most common situation that necessitates configuration of the net.slp.interfaces property occurs when multicast is not deployed on the network and broadcast is used instead. Other situations require careful thought and planning to avoid unnecessary duplicate responses or unreachable services.