Cisco Technology, Inc.

Madhavi Wunnava Chandra

Yi Yang

Alvaro E Retana

Russell Ivan White

David Anthony Cook

Kent Kinchu Leung

Alpesh S Patel

Milind Kulkarni

Abhay Kumar Roy

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

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

The present invention provides methods and apparatus for managing an IP address assigned to a Mobile Node. In one embodiment, the Mobile Node appends an extension to the registration request that is sent to its Home Agent, which indicates that the Mobile Node requests use of the IP address previously assigned to the Mobile Node for an additional period of time. When the Home Agent receives the registration request, it indicates whether a lease on the IP address previously assigned to the Mobile Node has been granted by the Home Agent for an additional period of time. In another embodiment, the Home Agent sends a first control message to determine whether the Mobile Node continues to use the IP address. The Home Agent then determines whether a second control message has been received in order to ascertain whether the Mobile Node continues to use the IP address previously assigned to the Mobile Node. The present invention is preferably performed when a Mobile Node returns to its home network, thereby enabling the Mobile Node to retain the IP address assigned to it.

Methods and apparatus for home address management at home agent for NAI based mobile nodes

Methods and apparatus for optimizing NAT traversal in Mobile IP are disclosed. Various mechanisms may performed independently or in combination with one another. A first mechanism enables one-way keep alive messaging to the Home Agent, while a second mechanism enables two-way keep alive messaging to the Home Agent, thereby enabling an entry in a NAT translation table to be maintained. The two-way keep alive messaging requires that the Home Agent send an acknowledgement message, while the one-way keep alive messaging does not. Keep alive messaging may be performed at the Mobile Node or the Foreign Agent. A third mechanism enables a Foreign Agent to encapsulate a registration request packet with the Foreign Agent care-of address in the source IP address field rather than an egress interface of the Foreign Agent. A fourth mechanism enables a Mobile Node to force a Home Agent to perform UDP tunneling.

Methods and apparatus for optimizing NAT traversal in Mobile IP

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

Methods and apparatuses for allowing mobile nodes to have access to mobility functions after being attached to their home networks are disclosed. The invention allows a home agent to authenticate a registration request and validate a DHCP-acquired home address even if no mobile bindings currently exist. Typically, a home agent will not create mobility bindings if a mobile node attaches itself to a home agent network segment. By using either cached information or DHCP resources, the home agent can approve a registration request.

DHCP based home address management of mobile IP clients

Methods and apparatus are disclosed that enable a Home Agent to be dynamically assigned to a mobile node. A Mobility Agent supporting Mobile IP enables a mobile node to be registered with either the Mobility Agent or another 'local' Home Agent, by receiving a registration request packet from the Mobile Node indicating that a key to be shared by the Mobile Node and an agent with which the Mobile Node is registering is requested. In addition, the agent with which the Mobile Node is registering (e.g., local Home Agent) may be assigned. For instance, a local Home Agent may be assigned if load balancing among multiple Home Agents is desired. A key to be shared by the Mobile Node and the agent with which the Mobile Node is registering is obtained. The key to be shared by the Mobile Node and the agent with which the Mobile Node is registering is then stored. A registration reply packet is then sent to the mobile node including the key to be shared by the Mobile Node and the agent with which the Mobile Node is registering. The mobile node may then re-register with the agent (e.g., local Home Agent) using the key.

Methods and apparatus for dynamic home agent assignment in mobile IP

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

Methods and apparatus for maintaining Mobile IP operation in a Home Agent are disclosed. In a Home Agent, a Mobile Node is registered and a registration entry is created in a mobility binding table for the Mobile Node. A multicast message is then sent to a virtual router group to which the Home Agent belongs and with which the Home Agent shares a virtual IP address. The multicast message notifies the virtual router group of the registration. A similar process may be performed when a Mobile Node is de-registered. When an active or non-active Home Agent is initialized, it sends a multicast mobility binding table request to the redundancy group indicating that bindings are requested. The Home Agent may then receive bindings in response to the request and update its mobility binding table with the received bindings.

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Cary, NC, United States of America

Madhavi Wunnava Chandra