Cisco Technology, Inc.

Suresh Katukam

Navindra Yadav

Abhay Kumar Roy

Venkataraman Anand

Venkata Tanikella

Shree N Murthy

Pradeep Singh

Anix Anbiah

In an example embodiment, a method is provided that assigns a sequence value to a host. The host is identified by a host network layer address. After the assignment, the host network layer address and the sequence value are included in an advertisement for transmission. In another example embodiment, another method is provided. Here, a first sequence value associated with the host network layer address is received from a network device. In addition, a second sequence value associated with the same host network layer address is received from a different network device. The first sequence value is ranked relative to the second sequence value and data is transmitted to the network device based on the ranking.

Host route convergence based on sequence values

In one embodiment, detecting a host device on a port of a forwarder switch in a network, detecting a movement of the host device from a first forwarder switch to a second forwarder switch, and multicast broadcasting an updated device information for the host device to a convergence group switches and a proximity group switches, where the convergence group switches includes switches in the network that are not configured as forwarder switches, and the proximity group switches include forwarder switches grouped together based on radio proximity is provided.

Host route convergence

In one example embodiment, a system and method are shown that includes calculating a first SPF tree for a first device, the first SPF tree including a root node and a first child node, the first device being the root node of the first SPF tree. Additionally, the system and method may include calculating a second SPF tree for a second device that is a neighbor of the first device, the second SPF tree including a root node and a first child node, the second device being the root node of the second SPF tree. Further, the system and method may include building a set of interested nodes including the second device, if the first child node if the first SPF tree and the first child node of the second SPF tree are distinct.

Link state protocol routing message containment

In one embodiment, providing multi-layer address security incorporating Layer 2 Media Access Control (MAC) addresses and corresponding Layer 3 Internet Protocol (IP) addresses for host machines on a routed access network is provided.

Address security in a routed access network

Methods and apparatus for enabling a protected circuit path to be created efficiently are disclosed. In accordance with one embodiment of the present invention, a method for creating a protected circuit path within an optical network system includes identifying a first node, a second node, and a third node. Once the nodes are identified, a pseudo link or a virtual link may be created between the second node and the third node. A first circuit path is then routed between the first node and the second node, and a second circuit path which protects that first circuit path is routed between the first node and the third node using the pseudo link.

Computing a path for an open ended uni-directional path protected switched ring

Methods and apparatus for defining an alternate circuit path within a network given nodal diverse or link diverse constraints are disclosed. According to one aspect of the present invention, a device for computing circuit paths between a first node and a second node within a network that has a plurality of elements includes a route generator and a list mechanism. The route generator computes a primary circuit path between the first node and the second node such that the primary circuit path includes a first element. The list mechanism identifies the first element as being inaccessible to an alternate circuit path. Using the list mechanism, the route generator computes an alternate circuit path that does not include the first element identified by the list mechanism. In one embodiment, the first element is a link. In another embodiment, the first element is a node.

Method and apparatus for computing a path in a system with nodal and link diverse constraints

Methods and apparatus for substantially minimizing single points of failure for circuit paths in networks with mixed protection schemes are disclosed. According to one aspect of the present invention, a method for routing circuit paths between a source and a destination of a network includes identifying a first available circuit path between the source and the destination. The first available circuit path includes a first plurality of links which each have an associated protection type. The method also includes determining a number protection changes associated with the first plurality of links, and assigning a first metric to the first available path that is based on the number of protection changes. Finally, the method includes identifying a selected available path to be used to pass information between the source and the destination based at least in part on the first metric.

Minimizing single points of failure in paths with mixed protection schemes

Methods and apparatus for enabling line-protected links to be included in path-protected segments of a unidirectional path-switched ring are disclosed. According to one aspect of the present invention, a method for computing a circuit path that includes a primary path between a start node and a destination node as well as an alternate path includes determining the primary path using a routing algorithm. The primary path includes a protectable segment which has a first line-protected link. The method also includes creating the alternate path using the routing algorithm. Creating the alternate path includes creating the alternate path between the start node and the end node with the alternate path arranged to protect at least the protectable segment which includes the first line-protected link. In one embodiment, the alternate path is created including the first line-protected link.

Computing a diverse path while providing optimal usage of line protected links

Methods and apparatus for defining an alternate circuit path within a network are described. According to one aspect of the present invention, a device for computing circuit paths between a first node and a second node within a network that has a plurality of elements includes a route generator and a list mechanism. The route generator computes a primary circuit path between the first node and the second node such that the primary circuit path includes a first element. The list mechanism identifies the first element as being inaccessible to an alternate circuit path. Using the list mechanism, the route generator computes an alternate circuit path that does not include the first element identified by the list mechanism. In one embodiment, the first element is a link. In another embodiment, the first element is a node.

Methods and apparatus for automatically routing paths in a network with a mixed protection domain. According to one aspect, a method for computing a primary path within a network includes identifying a plurality of potential paths which are characteristically similar and are arranged between the source node and the destination node and selecting a first potential path from the plurality of potential paths which are characteristically similar. The first potential path is considered for use as an actual path between the source node and the destination node, while the other potential paths included in the plurality of potential paths which are characteristically similar are not considered for use as the actual path between the source node and the destination node.

Method and apparatus for computing primary and alternate paths in mixed protection domain networks

Methods and apparatus for creating a primary path such that the ability to create a corresponding alternate path, if one exists, is effectively ensured are disclosed. According to one aspect of the present invention, a method for creating a circuit path includes selecting a first unprotected link, and identifying a first potential unprotected path segment that includes the first unprotected link and is arranged between a first node and a second node. A determination is automatically made regarding whether the first potential unprotected path segment has a corresponding first alternate path segment between the first node and the second node. If it is determined that the first potential unprotected path segment has a corresponding first alternate path segment, the first unprotected link is added to the first potential unprotected path segment. Then, the first potential unprotected path segment is designated as an unprotected path segment of the circuit path.

Method and apparatus for computing a primary path while allowing for computing an alternate path by using a blocked list

Methods and apparatus for automatically creating a circuit path that includes specified elements are disclosed. According to one aspect of the present embodiment, a method for computing a circuit path between a source node and a destination node of a network includes identifying at least a first element that is to be traversed by the circuit path such that the path passes from the source node, traverses the first element, then passes to the destination node. The method also includes routing a first segment of the circuit path automatically such that the source node and the first element are components of the first segment. In one embodiment, routing the first segment automatically includes routing the first segment automatically using a shortest path first algorithm.

Method and apparatus for computing a path through specified elements in a network

Methods and apparatus for automatically creating a path through a bi-directional line switched ring which uses common time slots are disclosed. According to one aspect of the present invention, an apparatus for creating a path between first and second nodes through a third node using first and second links includes a querying device, a comparator, and a routing device. The querying device identifies a first time slot of the first link for transferring data from the first node to the third node, and also identifies a second time slot associated with the second link for transferring data between the third node and the second node. The comparator determines when the first time slot and the second time slot are consistent, and the routing device computes the path between the first and second nodes using the first and second time slots when the first and second time slots are consistent.

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Rohnert Park, CA, United States of America

Suresh Katukam