Cisco Technology, Inc.

Juniper Networks, Inc.

Digital Equipment Corporation

Eric C Rosen

Yakov Rekhter

Clarence Filsfils

Eric Michel Levy-Abegnoli

James Neil Guichard

John E Drake

Francois Le Faucheur

Daniel C Tappan

William Stuart Mackie

Luc Louis Revardel

Adrian John Farrel

Parag Kumar Jain

Ijsbrand Wijnands

Ahmed Refaat Bashandy

Jim Guichard

Pradosh Mohapatra

Syed Kamran Raza

Bruce Stuart Davie

Ole Troan

Radia Joy Perlman

Keyur Patel

Arjen Boers

Ross W Callon

Vikram Nagarajan

Robert W Kebler

Peter Psenak

Eric Osborne

Luca Martini

Kapil Arora

Sina Mirtorabi

Robert H Thomas

Wei Luo

Princy T Elizabeth

John A Harper

John Mullooly

Mukhtiar Shaikh

Alex E Raj

Nagendra B Kumar

Jacob Ijsbrand Wijnands

Maciej Konstantynowicz

Theodore Qian

Gerhard Wieser

John J Mullooly

In some examples, a computing device comprises a first service function instance to apply a service function and a service function forwarder to: receive a first layer 3 routing protocol route advertisement that includes service function instance data for a second service function instance, the service function instance data indicating a service function type and a service identifier for the service function instance; receive a second layer 3 routing protocol route advertisement that includes service function chain data for a service function chain, the service function chain data indicating a service path identifier and one or more service function items; and send, to the second service function instance and based at least on determining a service function item of the one or more service function items indicates the second service function instance, a packet classified to the service function chain.

Distributing service function chain data and service function instance data in a network

In general, the disclosure describes techniques for communicating multicast group leave requests between two or more load-balanced, multi-homed PE routers included in an Ethernet Virtual Private Network (EVPN). The techniques of the disclosure enable the two or more PE routers to synchronize IGMP state and routing information amongst one another to ensure that the one of the multi-homed PE routers elected as the designated forwarder (DF) ceases forwarding the multicast group traffic to the CE router, even if it is not the PE router that receives the IGMP leave request.

Communicating IGMP leave requests between load-balanced, multi-homed provider-edge routers in an ethernet virtual private network

In one embodiment, a method comprises detecting, by a first provider edge router, a second provider edge router providing reachability to a prescribed destination address prefix via a protected next hop address; allocating, by the first provider edge router, a mirror forwarding table associated with the second provider edge router and identifying a destination used by the second provider edge router for reaching the prescribed destination address prefix; and the first provider edge router sending repair information to a Border Gateway Protocol (BGP)-free core network router in the core network, the repair information enabling the BGP-free core network router to add a context label and reroute a received data packet to the first provider edge router if the second provider edge router is unavailable, the context label enabling the first provider edge router to identify the destination in the rerouted data packet for delivery to the destination address prefix.

Scalable BGP protection from edge node failure using context labels in data packets identifying backup router mirror table

A method is provided in one example and includes receiving first address information from a protected node over a first label switched path having a first label. The first address information is associated with a first network element. A second label switched path has been previously established with the first network element. The method further includes establishing a targeted session with the first network element, assigning a second label to the second label switched path, and sending the second label to the first network element over the targeted session.

System and method for multipoint label distribution protocol node protection using a targeted session in a network environment

In one embodiment, a method comprises detecting, by a provider edge router configured for providing reachability for core network traffic to a prescribed destination address prefix, a backup provider edge router relative to the prescribed destination address prefix; allocating, by the provider edge router, a distinct protected next-hop address for reachability to at least the destination address prefix via the provider edge router; and sending via a core network, by the provider edge router, repair information for the prescribed destination address prefix to ingress provider edge routers and a BGP-free core network router in the core network, the repair information enabling the ingress provider edge routers to insert primary and backup switching labels into each data packet of the core network traffic enabling the BGP-free core network router to reroute the received packet to the backup provider edge router if the provider edge router is unavailable.

Scalable BGP protection from edge node failure using dynamically assigned labels in data packets

In one embodiment, a method includes receiving from a label distribution peer, a prefix/FEC to label mapping at a network device and processing the prefix/FEC to label mapping at the network device, wherein processing includes determining if a next hop interface of the prefix/FEC is in a same area as a link between the network device and the label distribution peer. The method further includes retaining the prefix/FEC to label mapping if the label distribution peer is a next hop for the prefix/FEC and if the next hop interface of the prefix/FEC is in the same area as the link between the network device and the label distribution peer, otherwise discarding the prefix/FEC to label mapping. An apparatus is also disclosed.

Selective label retention in a label switching network

In one embodiment, a device of a particular non-backbone routing domain in a computer network determines whether each of one or more routes is reachable within the particular non-backbone domain. The device may then generate a filtered set of label mappings having only those of the one or more routes reachable within the particular non-backbone domain. Accordingly, the device may advertise label mappings only of the filtered set to one or more neighboring devices.

Label distribution protocol label filtering

A method is provided in one example embodiment and includes receiving a label-mapping message at a first router. The first router does not record the label-mapping message. The method further includes sending the label mapping message toward a root router of a Multipoint Label Switched Path (MPLSP) in a network and, further, evaluating a path vector sent from the root router to identify whether a first router's address is part of the path vector. If the first router's address is present in the path vector then a label mapping associated with the path vector is not installed by the first router. In more detailed embodiments, the first router identifies that if the first router's address is part of the path vector, a loop is present in the network. If the first router's address is not part of the path vector, the label mapping associated with the path vector is recorded.

System and method for detecting loops for routing in a network environment

A method is provided for generating a backup route. Here, a route and a route distinguisher type associated with the route are received and a backup route is generated based on attributes of the route. A particular backup route distinguisher type that is associated with the route distinguisher type is assigned to the backup route. The backup route with the backup route distinguisher type are then advertised. Another method is provided that identifies the backup route. When the route and its route distinguisher type are received from the advertisement, an identification is made as to whether the route distinguisher type is assigned to a backup route. The route may then be designated as a backup route based on the identification.

Backup route generation in border gateway protocol

A virtual private network (VPN) is formed with a pair of autonomous systems (ASes) connected by each having at least two autonomous system border routers (ASBRs) connected to the corresponding ASBRs at the other AS, referred to as an Option B VPN-IPv4 network. Route reflectors (RRs) only reflect the best Border Gateway Protocol (BGP) paths, providing no backup BGP paths for fast convergence. Advantageously, an automatic route distinguisher (RD) rewrite component at the ASBRs creates unique prefixes and advertises the original RD as transitive attribute in an update message to external AS peers. Each RD gets mapped to another unique prefix at the ASBR and also that two ASBRs will create different unique prefixes. Thus, the route reflector sees different prefixes and reflects all of them. The ingress provider edge (PE) router can import the prefixes and correctly obtain the alternate paths for fast convergence.

Automatic RD rewrite technique to achieve fast convergence in inter-as networks

A technique maintains Interior Gateway Protocol (IGP) transparency of Virtual Private Network (VPN) routes when Border Gateway Protocol (BGP) is used as a Provider Edge Device (PE) to Customer Edge Device (CE) protocol in a computer network. According to the novel technique, a first CE generates a BGP advertisement to advertise one or more VPN routes of its customer network, the BGP advertisement having one or more transitive IGP attributes for the advertised routes. The first CE sends the BGP advertisement to a first PE, which then propagates the BGP advertisement among devices of a provider network maintaining the transitive IGP attributes. A second PE sends the BGP advertisement to a second CE, along with the transitive IGP attributes. Upon receiving the BGP advertisement, the second CE converts the BGP advertisement and transitive IGP attributes into corresponding IGP advertisements. The second CE may then propagate the IGP advertisements into its customer network as either internal VPN routes or as external routes accordingly.

Maintaining IGP transparency of VPN routes when BGP is used as a PE-CE protocol

A layer-2 virtual-private-network (L2-VPN) service with automatic discovery and connection establishment is provided within a wide-area, multiple-autonomous-system (AS) network according to one of two approaches. In the first approach, inter-AS tunnels are used to connect pairs of provider edge (PE) routers of different ASes, and the PE routers then establish signaling connections to each other which are used to create pseudowires that implement the layer-2 connectivity. A second approach utilizes so-called 'pseudowire switching' in which separate pseudowires are created within each AS and between ASes, and then the separate pseudowires are stitched together to form end-to-end connections. The first approach has the benefit of transparent operation provided by the tunnel, while the second approach requires fewer inter-AS signaling connections.

Inter-autonomous-system virtual private network with autodiscovery and connection signaling

A method and system for preventing misforwarding of packets from an MPLS network to a virtual private network are disclosed. The method includes receiving a packet at an ingress edge node of the MPLS network, associating a cookie with a label bound to a route by an egress edge node of the MPLS network, and inserting the cookie on an MPLS label stack at the ingress edge node. The packet is transmitted over the MPLS network to an egress edge node. The cookie allows the egress edge node to detect if the transmitted packet is misforwarded by comparing the cookie in the label stack of the transmitted packet with a stored cookie label at the egress edge node.

MPLS cookie label

Growing community of inventors

Arlington, MA, United States of America

Eric C Rosen