According to an embodiment of the application, a relay apparatus includes a destination storage unit configured to store the information about a destination of a multicast packet in association with a multicast address; a determination unit configured to determine whether the destination of the multicast packet is a first physical machine on the basis of the destination information stored in the destination storage unit in a migration process in which a virtual machine operating on the first physical machine is migrated to a second physical machine; and an addition unit configured to add information about the second physical machine to the destination information in the destination storage unit, the destination information corresponding to the multicast address that indicates the destination of the first physical machine, if the determination unit determines that the destination of the multicast packet is the first physical machine.