Large and/or complicated computer networks may contain multiple routing devices and multiple bridging devices within the topmost level of the network hierarchy. Such a network can be considered to consist of several top-level routing realms. A routing realm is, within the context of this document, a term referring to the network space behind a routing device, or the network space behind a group of interconnected bridging devices.
For example, a network containing two top-level routers R1 and R2, and four top-level bridging devices B1, B2, B3, and B4, can be considered to have three top-level routing realms: R1, R2, and (B1, B2, B3, B4).
In the case of a network which is provisioned by a single device at the top-level of the network, the network's routing realms, by virtue of fundamental networking principles, must utilize a distinct collection of Internet Protocol (IP) addresses, relative to the other routing realms within that network.
A network consisting of several top-level routing realms, where at least one of those routing realms is defined by a routing device, presents challenges to a top-level network provisioning device, because the provisioning device must successfully process routed and bridged traffic simultaneously. Such routed traffic is ISO Open Systems Interconnection Layer-3 traffic and such bridged traffic is ISO OSI Layer-2 traffic.
When an end-user device moves from one routing realm to another, since each routing realm must utilize a relatively unique collection of IP addresses, the IP address of the end-user device must change as the end-user device enters into a new routing realm. Thus, the existing provisioning device cannot handle such user who moves from a routing realm to another.
It is therefore desirable to provide a network provisioning device that can recognize that an end-user device has moved from a routing realm to another in a network comprising multiple routing realms, and handle this situation automatically.