Abstract: A subnet of an information network includes one or more mobile hosts, and a first interface of a home router. The first interface and the mobile hosts are assigned corresponding group addresses. Unicast addresses of packets received at a second interface of the home router and destined to members of the subnet, are mapped to the member's group addresses. Each mobile host sends a request to join a group corresponding to the group address assigned to the host, whenever the host links with the network at a new point of attachment. Thus, network routers can track the host as it moves its link with the network from one point of attachment to another, and unicast packets destined to the mobile host from a host outside the subnet are routed to the mobile host over the virtual link created between the home router and the mobile host.

Abstract: A subnet of an information network includes one or more mobile hosts, and a first interface of a home router. The first interface and the mobile hosts are assigned corresponding group addresses. Unicast addresses of packets received at a second interface of the home router and destined to members of the subnet, are mapped to the member's group addresses. Each mobile host sends a request to join a group corresponding to the group address assigned to the host, whenever the host links with the network at a new point of attachment. Thus, network routers can track the host as it moves its link with the network from one point of attachment to another, and unicast packets destined to the mobile host from a host outside the subnet are routed to the mobile host over the virtual link created between the home router and the mobile host.