DNS updating in communication network

In a communication network in which terminals ( 11 ) are mobile in the network, the mobility must be managed, and in particular the location of the mobile terminal needs to be determined. Networks each have an associated name server ( 13 ) and the name server ( 13 ) stores a care-of-address for the terminal ( 11 ), as well as a permanent address. As the terminal moves from one subnet of the network to another the care-of-address is changed to reflect the current subnet. Therefore, the input of the name of the mobile terminal ( 11 ) identifies via the care-of-address the subnet in which the terminal is currently located. The network is divided with domains each with its own name server ( 13, 14 ) as the terminal ( 11 ) moves from its home domain to a foreign domain, the name server ( 14 ) of that foreign domain may be updated with details of the mobile terminal ( 11 ) so that any query to the terminal ( 11 ) originating in the foreign domain may be resolved within that foreign domain. A care-of-address may be stored in the name server ( 14 ) of that foreign domain. Then, the address of the name server ( 14 ) of that foreign domain may be used as the care-of-address in the name server of the home domain ( 13 ).