US 8,724,627 B2Granted

Single-homing and active-active multi-homing in a virtual private LAN service

AssigneeCisco Technology, Inc.

InventorsClarence Filsfils, Sami Boutros, Samer M Salam, Ali Sajassi

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Abstract

In one embodiment, single-homing and active-active multi-homing is provided in a Virtual Private LAN Service (VPLS). A customer edge node actively communicates frames of a same Virtual Private Network (VPN) instance with two or more VPLS nodes of a VPLS network. The VPLS nodes are configured to appropriately forward frames throughout the VPLS network: without looping of a frame sent by the same external node back to the same external node, without flooding multiple copies of a frame to the same external node, and while performing learning of addresses in forwarding tables of said VPLS nodes such that said forwarding tables of said VPLS nodes converge despite frames of the same LAN service being received by said at least two of said VPLS nodes from the same external node.

Claims18

Dependent claims

A network, comprising:

a Virtual Private LAN Service (VPLS) network, including three or more interconnected VPLS nodes, with at least two of said VPLS nodes active-active multi-homed to a same external node for receiving Layer-2 (L2) packets of a same LAN service natively to the VPLS network from the same external node;
where said VPLS nodes are configured to appropriately forward frames throughout the VPLS network:
without looping of a frame sent by the same external node back to the same external node, and without flooding multiple copies of a frame to the same external node, while performing learning of addresses in forwarding tables of said VPLS nodes such that said forwarding tables of said VPLS nodes converge despite frames of a same VPLS instance of the same LAN service being contemporaneously received by said at least two of said VPLS nodes, encapsulated in a Multiprotocol Label Switching (MPLS) packets including in the label stack of the MPLS packets a MPLS label identifying the external node as the source of correspondingly received frames by said at least two of said VPLS nodes from the same external node, and the MPLS packets being correspondingly forwarded within the VPLS network by said at least two of said VPLS nodes.

A method, comprising:

receiving, by a first Virtual Private LAN Service (VPLS) node of a VPLS network from an external node external to the VPLS network, a first frame of a same VPLS instance of a same LAN service;
selecting, based on learned forwarding information including an identification of a plurality of VPLS nodes active-active multi-homed to a destination node, to forward a first Multiprotocol Label Switching (MPLS) packet to a particular VPLS node of the plurality of VPLS nodes active-active multi-homed to the destination node, with each of the plurality of VPLS nodes active-active multi-homed to the destination node both contemporaneously communicating packet traffic of the same VPLS instance of the same LAN service with other nodes in the VPLS network and communicating packet traffic of the same VPLS instance of the same LAN service with the destination node;
creating, by the first VPLS node, the first MPLS packet encapsulating said received first frame, and including in the label stack of the MPLS packet a MPLS label identifying the external node as the source of the first frame;
and sending, by the first VPLS node, the first MPLS packet to the particular VPLS node of the VPLS network for communicating the first frame to a destination node external to the VPLS network.

1 more element

A method, comprising:

receiving, by a first Virtual Private LAN Service (VPLS) node of a VPLS network from a second VPLS node of the VPLS network, a Multiprotocol Label Switching (MPLS) packet created by the second VPLS node encapsulating a frame of a same VPLS instance of a same LAN service, and including in its label stack a first MPLS label identifying an external node as the source of the frame having been received by the second VPLS node from the external node;
and address learning, by the first VPLS node, that the external node is actively coupled to the second VPLS node based on the first MPLS label identifying the external node as the source of the frame;
wherein the external node is an active-active multi-homed node external to the VPLS network that is contemporaneously communicating packets of the same VPLS instance of the same LAN service with at least the first VPLS node and the second VPLS node, and with each of the first and second VPLS nodes contemporaneously communicating packets of the same VPLS instance of the same VLAN service with nodes in the VPLS network.

Dependencies are inferred from the claim text.

Facts

Application: 13/031,909Filed 22 Feb 2011
Published: US 2012/0213222 A123 Aug 2012
Granted: 13 May 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04L 12/4641
Interconnection of networks: virtual LANs, VLANs, e.g. virtual private networks [VPN]
H04L 45/50
Routing or path finding of packets in data switching networks: using label swapping, e.g. multi-protocol label switch [MPLS]
H04L 45/16
Routing or path finding of packets in data switching networks: multipoint routing
H04L 45/68
Routing or path finding of packets in data switching networks: pseudowire emulation, e.g. IETF WG PWE3