Abstract: A method and apparatus for recovering from a controlled failover of a BGP speaker is provided. A user sends, to a network element, a request to switch a designation of an active Border Gateway Protocol (BGP) speaker of the network element from a first BGP speaker to a second BGP speaker. After receiving the request, the network element pauses operation of a transport for BGP. Routing data, which describes a state of a first routing information base (RIB) maintained by the active BGP speaker, is transferred from the first BGP speaker to the second BGP speaker. Thereafter, the first BGP speaker may instruct the second BGP speaker to become the active BGP speaker. After the second BGP speaker becomes the active BGP speaker, the second BGP speaker resumes operation of the BGP transport.

Abstract: A method and apparatus for recovering from a controlled failover of a BGP speaker is provided. A user sends, to a network element, a request to switch a designation of an active Border Gateway Protocol (BGP) speaker of the network element from a first BGP speaker to a second BGP speaker. After receiving the request, the network element pauses operation of a transport for BGP. Routing data, which describes a state of a first routing information base (RIB) maintained by the active BGP speaker, is transferred from the first BGP speaker to the second BGP speaker. Thereafter, the first BGP speaker may instruct the second BGP speaker to become the active BGP speaker. After the second BGP speaker becomes the active BGP speaker, the second BGP speaker resumes operation of the BGP transport.

Abstract: A method and apparatus for recovering from a controlled failover of a BGP speaker is provided. A user sends, to a network element, a request to switch a designation of an active Border Gateway Protocol (BGP) speaker of the network element from a first BGP speaker to a second BGP speaker. After receiving the request, the network element pauses operation of a transport for BGP. Routing data, which describes a state of a first routing information base (RIB) maintained by the active BGP speaker, is transferred from the first BGP speaker to the second BGP speaker. Thereafter, the first BGP speaker may instruct the second BGP speaker to become the active BGP speaker. After the second BGP speaker becomes the active BGP speaker, the second BGP speaker resumes operation of the BGP transport.

Abstract: A method is disclosed for prioritized processing of routing information in a network element. A priority is assigned to routing information received at the network element. The priority and the routing information are stored in a Routing Information Base (RIB) of the network element. The routing information is transferred from the RIB to a Forwarding Information Base (FIB) of the network element according to the priority assigned to the network element.

Abstract: A method of improving convergence in networks that use path vector protocols. In one embodiment using Border Gateway Protocol (BGP) for inter-domain route and reachability communication, nodes that need to remove routes using EBGP NLRI announcements send BGP WITHDRAW messages containing a new route originator attribute that identifies an originator of a specified withdrawn route. A receiving node removes the specified route from its routing information base (RIB), and matches the originator to other paths in the RIB. Matching paths are marked as ineligible for consideration in a best path computation, thereby preventing the use of routes that are unreachable but not yet withdrawn by an originating node. The approach causes faster BGP convergence, reduces unnecessary route flapping, and alleviates unnecessary route dampening.

Abstract: A method of improving BGP convergence in a packet-switched network comprises receiving, at a router in the packet-switched network, an advertisement of a first route that includes alternate route information indicating that an alternate route is available; storing the alternate route information in association with the first route; detecting a change in network reachability of the first route, and in response thereto, determining if the alternate route information is stored for the first route, and if so: awaiting, for a particular time, an advertisement of an alternate route; storing and using the alternate route in place of the first route.

Abstract: 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.

Abstract: A method of improving BGP convergence in a packet-switched network comprises receiving, at a router in the packet-switched network, an advertisement of a first route that includes alternate route information indicating that an alternate route is available; storing the alternate route information in association with the first route; detecting a change in network reachability of the first route, and in response thereto, determining if the alternate route information is stored for the first route, and if so: awaiting, for a particular time, an advertisement of an alternate route; storing and using the alternate route in place of the first route.

Abstract: A method of improving convergence in networks that use path vector protocols. In one embodiment using Border Gateway Protocol (BGP) for inter-domain route and reachability communication, nodes that need to remove routes using EBGP NLRI announcements send BGP WITHDRAW messages containing a new route originator attribute that identifies an originator of a specified withdrawn route. A receiving node removes the specified route from its routing information base (RIB), and matches the originator to other paths in the RIB. Matching paths are marked as ineligible for consideration in a best path computation, thereby preventing the use of routes that are unreachable but not yet withdrawn by an originating node. The approach causes faster BGP convergence, reduces unnecessary route flapping, and alleviates unnecessary route dampening.

Abstract: 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.

Abstract: A method is disclosed for prioritized processing of routing information in a network element. A priority is assigned to routing information received at the network element. The priority and the routing information are stored in a Routing Information Base (RIB) of the network element. The routing information is transferred from the RIB to a Forwarding Information Base (FIB) of the network element according to the priority assigned to the network element.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for recovering from a controlled failover of a BGP speaker is provided. A user sends, to a network element, a request to switch a designation of an active Border Gateway Protocol (BGP) speaker of the network element from a first BGP speaker to a second BGP speaker. After receiving the request, the network element pauses operation of a transport for BGP. Routing data, which describes a state of a first routing information base (RIB) maintained by the active BGP speaker, is transferred from the first BGP speaker to the second BGP speaker. Thereafter, the first BGP speaker may instruct the second BGP speaker to become the active BGP speaker. After the second BGP speaker becomes the active BGP speaker, the second BGP speaker resumes operation of the BGP transport.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.