In a packet switched network, first said network address are allocated to a first mobile node being served via a communications link by a first access node, at least a first routing path in related infrastructure being directed to the first access node for the first network address.Routing in said infrastructure is altered when the first mobile node receives service from a second access node, such that at least a second routing path in the infrastructure is directed to the second access node for the first network address, the second routing path being defined at least in part by one or more host-specific routing entries. During a period of subsequent inactivity, the one or more host-specific routing entries are removed from the infrastructure such that the mobile node has no current routing path. During the period of inactivity, two separate states are provided for the mobile node: a) a state in which the mobile node retains the first network address; and b) a state in which the first network address may be reallocated to a different mobile node.