摘要:
A method of constructing a backup path in an autonomous system (AS) for failure of an inter-AS link is described. The method comprises identifying an alternate inter-AS path and constructing a tunnel to an end point on the alternate path.
摘要:
A method of constructing a backup path in an autonomous system (AS) for failure of a first inter-AS link serving a first set of prefixes is described. The method comprises identifying an alternate inter-AS link serving said plurality of prefixes and constructing a tunnel thereto.
摘要:
A packet data router comprises one or more first circuit boards comprising one or more first processors and first logic circuits programmed to perform packet data forwarding and packet data router control plane functions; and one or more second circuit boards comprising one or more second processors and second logic circuits programmed to perform only Border Gateway Protocol (BGP) route reflection server (RRS) functions. A distributed BGP route reflector system with the disclosed architecture distributes route reflection server software to a dedicated control board so that processing route reflection functions does not impact packet forwarding or protocol instances that converge forwarding tables.
摘要:
A method and system for protecting valuable resources within an autonomous system network. Address prefixes within the system are designated as valuable and a flag bit is associated with the address within routing tables of routers of the network. Interfaces to border routers are identified and when packets are received at those interfaces, the packets are flagged with a flag or tag bit. The destination address of the received packet is compared to the flag bit associated with the valuable resource prefix, and if the packet is directed to that resource the packet is dropped and/or logged, but the packet is not forwarded to that resource. In specific cases an interface from an external source may be configured to not create the flag or tag bit, wherein that packet will be delivered to the destination prefix of the packet.
摘要:
A fast reroute (FRR) technique that may be deployed at the edge of a network having first and second edge devices coupled to a neighboring routing domain. If the first edge device detects a node or link failure that prevents it from communicating with the neighboring domain, the first edge device reroutes at least some data packets addressed to the neighboring domain to the second edge device. The second edge device receives the rerouted packets and then forwards the packets to the neighboring domain. Notably, the second edge device is not permitted to reroute the received packets a second time, e.g., upon identifying another inter-domain node or link failure. As such, loops are avoided at the edge of the network and packets are rerouted to the neighboring routing domain faster and more efficiently than in prior implementations.
摘要:
A method of managing forwarding of data in a first autonomous system (AS) is described. The first AS includes a plurality of border routers having inter-domain links to one or more remote AS's and an associated exterior communications protocol. The border routers use an interior communications protocol with other border routers in the first AS using primary tunnels. The method comprises the steps, performed at a first border router having a primary route via an inter-domain link to a remote AS, of constructing an alternate route to the remote AS via second border router in the first AS, instigating a backup tunnel to the second border router upon failure of the primary route and sending a failure message to the other border routers.
摘要:
A method of implementing a backup path in an autonomous system (AS) for failure of an inter-AS link is described. The method comprises forwarding data elements destined for the failed link via a backup path and including a loop prevention attribute in the packet.
摘要:
A fast reroute (FRR) technique is implemented at the edge of a computer network. In accordance with the technique, if an edge device detects a node or link failure that prevents it from communicating with a neighboring routing domain, the edge device reroutes at least some data packets addressed to that domain to a backup edge device which, in turn, forwards the packets to the neighboring domain. The rerouted packets are designated as being “protected” (i.e., rerouted) data packets before they are forwarded to the backup edge device. To that end, the edge device incorporates an identifier into the rerouted data packets to indicate that the packets are being FRR rerouted. The identifier may be a predetermined value stored at a known location in the rerouted packets'encapsulation headers, such as in their MPLS or IP headers. Upon receiving a data packet containing the identifier, the backup edge device is not permitted to reroute the packet a second time.
摘要:
A partial best path technique distributes route selection in a routing protocol implementation on a router. The technique also ensures that announced paths received from peers of the router (i.e., a “load”) are compared in a correct order to select best paths that are then used by the router to forward packets and to advertise to the peers. When employed in a distributed architecture, the technique further reduces memory usage. To that end, the partial best path technique enhances a best path selection algorithm executed by the router to enable dispersion of the received path load among processing nodes or elements of the router, while maintaining the ordering requirement of the algorithm. The partial best path technique essentially provides an enhancement to the best path selection algorithm that selects a subset of paths from a plurality of paths, with that subset being the minimal subset needed to select the best paths.
摘要:
A method and apparatus is described for Border Gateway Protocol (BGP) route management and routing policy modeling. In one aspect, the performance of one or more actions associated with one or more routes is disallowed. One or more routing policies associated with the one or more routes are configured. The performance of the one or more actions is then allowed. In one feature of the aspect, the one or more actions comprise forwarding packets on the one or more routes. The one or more actions may also comprise advertising the one or more routes to BGP peers.