Cisco Technology, Inc.

Peram Marimuthu

William Norman Eatherton

Priyank Ramesh Warkhede

Abhijit Patra

Shyamsundar Nandkishor Maniyar

Ganesh Sadasivan

Jeffrey Ym Wang

Milton Y Xu

Xiaoxue Ma

Rengabashyam Srinivas

Methods and apparatus are disclosed for defining flow types and instances thereof such as for identifying packets corresponding to instances of the flow types. A flow type is defined and includes a set of properties including at least one of the possible properties selectable when defining a flow type. An instance of the flow type is defined and a set of corresponding associative memory entries is generated. A lookup word generator of a packet processing engine is typically notified of the use of the flow type, and one or more lookup words are generated typically by extracting fields from a received packet and/or from other sources. Based on a result of lookup operations on the set of associative memories entries using the generated one or more lookup words, the received packet can be identified as whether it matches or does not match the instance of the flow type.

Methods and apparatus for defining flow types and instances thereof such as for identifying packets corresponding to instances of the flow types

Reverse path forwarding protection of packets is provided using automated population of access control lists based on a forwarding information base. One implementation identifies a lookup value by extracting one or more values including a source address from a packet. An access control list lookup operation is performed on an access control list based on the lookup value to identify a permit or a deny condition, the access control list including multiple access control list entries. The packet is processed based on the permit or the deny condition identified in by the access control list lookup operation, this processing the packet based on the permit condition includes performing a forwarding lookup operation on a representation of a forwarding information base to identify a location and forwarding the packet to the location. The access control list entries are automatically generated based on a forwarding information base.

Reverse path forwarding protection of packets using automated population of access control lists based on a forwarding information base

Only one point to multipoint virtual circuit (p2mp VC) is used within a router to handle all of the sources for a particular multicast group when other particulars of the multicast group are identical within that router. The router receiving a multicast packet for a particular multicast group identifies the source and the group number by reading fields of the incoming packet, identifies the input port of the router, and identifies the output port list. The input port of the router, the group number G, and the output port list are used by the router in establishing and identifying a point to multipoint VC within the router. The invention identifies all packets arriving at that particular input port, having the same multicast group number G, and having the same output port list, and transfers them to the identified VC. The VC is associated in the routing table with the output list of ports from which copies of the multicast packet are transmitted. Accordingly, only one VC is needed to transfer packets arising from any source of the multicast group so long as the multicast packets arrive on the same port of the router and have the same output port list.

VC sharing for multicast in a computer network

Methods and apparatus are disclosed for allocating and using range identifiers as input values to associative memories, especially binary content-addressable memories (CAMs) and ternary content-addressable memories (TCAMs). In one implementation, each of multiple non-overlapping intervals are identified with one of multiple unique identifiers. An indication of a mapping between the multiple non-overlapping intervals and the multiple unique identifiers is maintained. A particular unique identifier is determined from said multiple unique identifiers based on a value and said multiple non-overlapping intervals. A lookup operation is performed on an associative memory using the particular unique identifier to generate a result. One implementation uses a trie representation of a range tree of the intervals to derive the unique identifiers. Moreover, one implementation evaluates and selects among various possible trie representations, especially to determine identifiers such that a TCAM prefix may match multiple intervals corresponding to a desired range.

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Sunnyvale, CA, United States of America

Peram Marimuthu