Cisco Technology, Inc.

Ciena Corporation

Pranav Mehta

Sami Boutros

Pradosh Mohapatra

David Delano Ward

Muthurajah Sivabalan

John Galen Scudder

Himanshu Shah

Stefan Olofsson

Jayant Kumar Bhardwaj

Peng He

Arjun Sreekantaiah

Robert Rszuk

Michael J Barnes

Systems and methods include determining one or more Layer 3 Virtual Private Networks (L3VPNs) supported at the router; and advertising the one or more L3 VPNs to one or more routers in the Segment Routing network with each advertisement including a service Segment Identifier (SID) for each of the one or more L3VPNs and one of a node SID for the router or an Anycast SID when the router is connected to a Multi-Home site. The steps can further include transmitting a Layer 3 (L3) packet for an L3 VPN of the one or more L3 VPNs with a destination SID and a service SID of the L3VPN. The advertisement can include encapsulation as an IPv6 prefix containing both the node SID for the router and the service SID, and wherein prefixes are treated as attributes of a route.

Optimized layer 3 VPN control plane using segment routing

A node includes one or more line cards interconnected to one another via a switching fabric and configured to implement a data plane; and a first router processor and a second router processor communicatively coupled to the one or more line cards, and each configured to implement a separate control plane, such that the node appears in a link-state database as two separate nodes. Responsive to an in-service software upgrade, the first router processor is upgraded and down while the second router processor is active, thereby preserving routing and forwarding. The one or more line cards include a first Virtual Local Area Networking (VLAN) for the first router processor and a second VLAN for the second router processor, and the first VLAN and the second VLAN are associated with a same physical interface on the one or more line cards.

In-service software upgrade systems and methods utilizing two router processors in a network element

In one embodiment, a packet switching device determines backup forwarding paths based on route distinguisher correlation values. A route distinguisher correlation value is some value associated with multiple routes, which allows a packet switching device to consider routes associated with a same route distinguisher correlation value, but having different route distinguishers and a same prefix to be considered as going to a same destination. Examples of route distinguisher correlation value used in one embodiment include, but are not limited to: scalar values, a route distinguisher of a different route, a virtual private network associated with a different route; a route target associated with the a different route; or a Border Gateway Protocol (BGP) Next-hop address associated with a different route.

Determining backup forwarding paths based on route distinguisher correlation values

In one or more embodiments, an architecture is provided that may intercept a route update message and compare AS numbers of an AS path with a list of AS numbers known or inferred to be problematic. In one or more embodiments, the problematic AS numbers can be substituted with a local AS number such that loop detection checks enforced automatically on many networks do not discard the message and/or prevent connectivity between two disparate networks.

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A technique is provided for graceful restart of a Border Gateway Protocol (BGP) router that uses a local store on the restarting router that stores prefixes on all routes or the 'group best path' information on all BGP peers having a common Autonomous System (AS) number. This local store is used to run best path computations on the restarting router, rather than first awaiting receipt of route information from peers to speed the restart process. Updates are then transmitted to peers using the best path data and an end-of-Routing Information Base (RIB) message it transmitted by the restarting router to indicate that all information has now been sent by the restarting router. Thereafter the restarting router processes incoming updates from peers as received (or these peers routes are timed-out), remaining stale paths are deleted and any changed best paths, based upon the newly received updates, are then transmitted to peers.

System and method for speeding border gateway protocol graceful restart

Growing community of inventors

San Jose, CA, United States of America

Pranav Mehta