Embodiments may include a load balancer that receives a request packet sent by a remote client to an original destination address of multiple network addresses serviced by the load balancer, and selects according to a load balancing protocol, a host computer of a plurality of host computers to process the request. The load balancer may, from among a plurality of ports on the selected host computer, select a particular port having a one-to-one association with the original destination address, the association specified by mapping information accessible to the load balancer, and send the request packet to the selected port on the selected host computer. The mapping information accessible to the selected host computer specifies a one-to-one association between the selected port and the original destination address. Sending the request packet to the selected port conveys that address to the selected server without that address being included in that packet.