The present disclosure relates scaling out servers that performs Layer 3 (L3) termination. In particular, the server includes: a packet receiving unit which receives a packet from any load balancer performing L3 termination via an Layer 2 (L2) switch; an assignment unit which, by referencing a MAC/MARK number correspondence table in a storage unit, assigns to the received packet a MARK number that corresponds to a transmission source MAC address; a recording unit which records a MARK number for connection of the received packet in a connection/MARK number correspondence table; and a packet transmission unit which, when a reply packet to the received packet is to be transmitted, routes the reply packet via the L2 switch by acquiring, from a MARK number/GW correspondence table in the storage unit, an IP address of a load balancer corresponding to the MARK number associated with the connection of the received packet.