A method and apparatus are provided for sending a data packet through a
network. The network has public and private realms separated by an
interface device. A client in the private realm performs the method. The
method includes determining if a destination address of the data packet
corresponds to the private realm or to the public realm and retrieving a
source address for the client based on the destination address of the
packet. The method also includes assigning a retrieved address to be the
source address of the data packet.