A method for allocating network addresses comprises providing an address
pool comprising a plurality of network addresses and then dividing the
address pool into a plurality of address sub-pool that comprise a unique
subset of the network addresses of the address pool. Each of the
sub-pools is available for use by any one of a plurality of routing
devices of a network access server. The method then comprises receiving a
request to assign a first network address to a first user, allocating a
first address sub-pool of the plurality of address sub-pools to a first
routing device of the plurality of routing devices and transmitting a
first message to the other routing devices to indicate that the first
address sub-pool has been allocated. The method additionally comprises
assigning the first network address to the first user from the first
address sub-pool and advertising an aggregate route for the first address
sub-pool over a network.