The class instance procedures, []metric../ns-2/route-proto.tclrtPeer::metric and []preference../ns-2/route-proto.tclrtPeer::preference, take one destination and value, and set the respective array variable. The procedures, []metric?../ns-2/route-proto.tclrtPeer::metric? and []preference?../ns-2/route-proto.tclrtPeer::preference?, take a destination and return the current value for that destination. The instance procedure []addr?../ns-2/route-proto.tclrtPeer::addr? returns the address of the peer agent.