Cisco Technology, Inc.

David Anthony Cook

Alvaro E Retana

Russell Ivan White

Yi Yang

Madhavi Wunnava Chandra

Abhay Kumar Roy

James L Ng

Russel Ivan White

Alvaro Enrique Retana

A method for communicating packets in a network environment is provided that includes receiving a packet at a network element and identifying a sequence number included in the packet that correlates to awareness information associated with one or more adjacent network elements. A table included in the network element may be updated in order to account for the awareness information included within the packet that has not been accounted for by the network element. In cases where the awareness information included in the packet has already been accounted for, the packet may be ignored.

System and method for exchanging awareness information in a network environment

In one embodiment, a method includes receiving on a first communication link at a local router all routing information at a certain level of detail for each router of multiple routers communicating in a first flooding domain. A measure of distance is determined from a particular router in the first flooding domain to the local router. It is determined whether the measure of distance exceeds a threshold. If the measure of distance exceeds the threshold, then summary routing information with less than the certain level of detail is determined for the particular router. Also, certain routing information is sent over a different second communication link at the local router. The certain routing information includes the summary information for the particular router, and all routing information at the certain level of detail for a subset of routers communicating in the first flooding domain, which subset excludes the particular router.

Automatic overlapping areas that flood routing information

Each router in a network is configured for generating router advertisement messages according to a flooding distance vector routing protocol. Each router advertisement message output according to the flooding distance vector routing protocol includes reachability information for at least one destination, and an originating router identifier indicating a router having originated the reachability information. If any router receiving the router advertisement message detects a match between the originating router identifier and the corresponding assigned router identifier, the received router advertisement message is disregarded during calculation of the best paths from the network. If the originating router identifier identifies another router, the router floods the received router advertisement message to other ports, and output its own router advertisement message based on the received router advertisement message and that specifies the originating router identifier from the received router advertisement message.

Arrangement for preventing count-to-infinity in flooding distance vector routing protocols

An apparatus for communicating packets in a network environment is provided that includes a first network element that includes a first neighbor list, the first network element being coupled to a second network element and a third network element. The first network element is operable to receive a second neighbor list from the second network element and a third neighbor list from the third network element. The first network element is further operable to determine one or more overlaps provided by the second and third neighbor lists when compared to the first neighbor list, the first network element relaying an update that it receives based on the one or more overlaps.

System and method for controlling the flooding of information in a network environment

An exploration technique allows a router to efficiently determine capabilities and configuration of a neighbor (peer) router. In addition, the technique enables peer routers of an adjacency to negotiate a capability 'outside' of a protocol, such as a routing protocol, before a routing session is established between the routers. In this context, the term 'outside' of the protocol denotes that there is no field within a protocol packet (message) implementation that can be used to negotiate the capability. Moreover, the inventive technique obviates the need to manually configure a router to support a particular capability and interoperate correctly within a network of routers that both support and are unaware of the capability.

TTL exploration technique for determining capabilities and configuration of a peer router

A method for verifying a validity of a path is provided that includes receiving an advertisement communication at a first autonomous system from a second autonomous system, the advertisement communication including a list of one or more connected autonomous systems. The method also includes identifying whether the first autonomous system claims a connection to the second autonomous system and whether the second autonomous system claims a connection to the first autonomous system such that two-way connectivity is established between the autonomous systems. In response to the establishment of the two-way connectivity, a directed graph is constructed that includes two nodes representing the first and second autonomous systems respectively. An edge may be formed that connects the two nodes.

System and method for verifying the validity of a path in a network environment

A method and apparatus are presented supporting shortest path first (SPF) routing of data packets over a network by establishing link-state data at an router. Link-state data indicates direct links between the router and a different router and establishes an adjacency relationship with the different node. Initial link-state data is stored at a first router. After the initial link-state data is stored, a hello message is received at the first router. The hello message indicates a direct connection with a different second router on one network segment. Based on the initial link-state data, it is determined whether establishing an adjacency relationship with the second router is sufficiently valuable. If not, then an adjacency relationship is not established with the second router in response to the hello message. A shortest path first routing for a data packet traversing the network is determined based on one or more adjacency relationships indicated in link-state data stored at the first router.

Techniques for reducing adjacencies in a link-state network routing protocol

A method for communicating packets in a network environment is provided that includes communicating, by a first network element, a first summary update to a second network element. The method further includes receiving a second summary update from the second network element. The exchange of the first and second summary updates achieves adjacency between the first and second network elements. The first and second summary updates include, at least, locally generated state information and a single link state.

System and method for synchronizing link state databases in a network environment

A method for reducing information being transmitted in a network is provided that includes gleaning routing information being communicated by a first network element, the routing information being stored such that the routing information may be accessed. An adjacency protocol may be executed between the first network element and a second network element that allows for a data exchange between the first and second network elements. The first network element does not communicate the routing information gleaned by the second network element during the data exchange associated with the adjacency protocol.

System and method for reducing information being transmitted in a network environment

A method and apparatus are presented for determining network nodes for aggregating addresses in routing information used for routing data packets over a network. Link data and reachability data are received. Link data indicates direct links between each of multiple candidate routers of a network and a different router or a network segment. Reachability data indicates a set of one or more contiguous network addresses that can be reached on each link described in the link data. A measure of possible aggregation of contiguous network addresses is determined at the candidate routers based on the link data and the reachability data. A preferred router to aggregate addresses in routing information sent between routers in the network is determined among the candidate routers based on the measure of possible aggregation at each candidate router.

Growing community of inventors

Raleigh, NC, United States of America

David Anthony Cook