A method for providing BGP route updates in an MPLS network is disclosed. The route update is performed at a router having a forwarding information table containing BGP routes and an internal label, and an adjacency table containing BGP/VPN labels and said internal label. The internal label corresponds to at least one IGP route and has an adjacency associated therewith. The method includes updating the adjacency associated with the internal label following an IGP route change.
Customer edge (CE) to CE device verification checks initiate routes from available CEs as a set of path verification messages, destined for remote CE routes serving a remote VPN. An extended community attribute, included among the attributes of the path verification message, stores the identity of the originating CE router. The path verification message propagates across the network, and transports the identity of the originating CE router because the originator identity is not overwritten by successive routing. Upon receipt by the remote CE, the originator is determinable from the extended community attribute. A further reachability field is also included in the extended community attribute and indicates whether per CE or per prefix is appropriate for the particular route in question. In this manner, CE-CE connectivity checks identify CEs which are reachable from other CEs. Accordingly, such a mechanism allows for route reachability aggregation on a per-CE or per-prefix reachability basis.
A technique efficiently routes Internet Protocol (IP) traffic on paths between customer edge devices (CEs) across a provider network ("CE-CE paths") in a computer network. According to the novel technique, a path computation element (PCE), e.g., a provider edge device (PE), may learn dynamic link attribute information of remote links from the provider network to one or more remote CEs (e.g., "PE-CE links" or "CE-PE links"). A multi-homed requesting CE requests from the PCE a set of CE-CE path metrics (e.g., costs) to one or more remote destination address prefixes, e.g., via each multi-homed CE-PE link from the requesting CE. In response to the request, the PCE computes the set of available CE-CE paths and current metrics to the remote destination address prefixes and returns the corresponding CE-CE path metrics to the requesting CE. The requesting CE modifies its IP forwarding entries accordingly in order to perform IP traffic routing corresponding to the CE-CE path metrics (e.g., asymmetrical load balancing) across its multi-homed CE-PE links.
