Abstract: A network device creates a forwarding table that includes information associated with a set of destinations in a network, and determines next hops for the set of destinations. The network device populates the forwarding table with information associated with the next hops, and stores the forwarding table. The forwarding table is used to forward a multicast packet toward a multiple destinations, and includes separate entries that depend upon routes the multicast packet is to traverse towards destinations with multiple choices for next hops.

Abstract: A network device creates multiple forwarding tables, and each forwarding table includes information associated with a first set of destinations and a second set of destinations. The first set of destinations is different than the second set of destinations. The network device determines, for each forwarding table, next hops for the first set of destinations, and determines, for each forwarding table, equal cost multipath next hops for the second set of destinations. The network device populates the multiple forwarding tables with information associated with the next hops and the equal cost multipath next hops, and the multiple forwarding tables are used to forward a multicast packet toward multiple destinations.

Abstract: A network device creates a forwarding table that includes information associated with a set of destinations in a network, and determines next hops for the set of destinations. The network device populates the forwarding table with information associated with the next hops, and stores the forwarding table. The forwarding table is used to forward a multicast packet toward a multiple destinations, and includes separate entries that depend upon routes the multicast packet is to traverse towards destinations with multiple choices for next hops.

Abstract: A network device creates multiple forwarding tables, and each forwarding table includes information associated with a first set of destinations and a second set of destinations. The first set of destinations is different than the second set of destinations. The network device determines, for each forwarding table, next hops for the first set of destinations, and determines, for each forwarding table, equal cost multipath next hops for the second set of destinations. The network device populates the multiple forwarding tables with information associated with the next hops and the equal cost multipath next hops, and the multiple forwarding tables are used to forward a multicast packet toward multiple destinations.

Abstract: Link failure messages are sent through a network to accelerate convergence of routing information after a network fault. The link failure messages reduce the oscillations in routing information stored by routers, which otherwise can cause significant problems, including intermittent loss of network connectivity as well as increased packet loss and latency. For example, the link failure messages reduce the time that a network using a path vector routing protocol, such as the Border Gateway Protocol (BGP), takes to converge to a stable state. More particularly, upon detecting a network fault, a router generates link failure information to identify the specific link that has failed. In some types of systems, the router communicates the link failure information to neighboring routers as well as a conventional update message withdrawing any unavailable routes. Once other routers receive the link failure information, the routers do not attempt to use routes that include the failed link.

Abstract: Link failure messages are sent through a network to accelerate convergence of routing information after a network fault. The link failure messages reduce the oscillations in routing information stored by routers, which otherwise can cause significant problems, including intermittent loss of network connectivity as well as increased packet loss and latency. For example, the link failure messages reduce the time that a network using a path vector routing protocol, such as the Border Gateway Protocol (BGP), takes to converge to a stable state. More particularly, upon detecting a network fault, a router generates link failure information to identify the specific link that has failed. In some types of systems, the router communicates the link failure information to neighboring routers as well as a conventional update message withdrawing any unavailable routes. Once other routers receive the link failure information, the routers do not attempt to use routes that include the failed link.

Abstract: A method for minimizing advertising of metrics in a network. The described invention minimizes advertising of metrics by providing for each node to identify to the other nodes the metrics it will utilize in path selection. Each node then advertises only those metrics which are utilized by at least one other node in the network.

Abstract: A checksum is generated for a bit string in an information packet to be transmitted across a network, by grouping contiguous bit groups in the bit string and, in sequence, processing each of the bit groups to produce a checksum component for each bit group, with the final checksum for the bit string being produced as an accumulation of the checksum components.

Abstract: Stored information used for routing packets of a network of nodes interconnected by links. A link state packet is sent to the first node indicating the states of links connected to some given node in the network. At the first node, an attempt is made to derive from the link state packet sent in step (a), the states of the links. If the states of fewer than all of the links connected to the given node are derived in step (b), the stored information used for routing packets is updated using the derived link states without regard to other link state packets sent to the first node. Another aspect features organizing, at a node in a network of nodes interconnected by links, a database of entries concerning respective links, by (a) providing indicators associated with the entries, (b) when a link becomes inoperable, setting or clearing the indicator associated with the entry related to the link, and (c) when the link becomes operable, clearing or setting the indicator.

Abstract: A data communication network subject to bursty traffic employs a bandwidth allocation scheme to avoid congestion. When a source node has a burst of traffic to send, it first sends a bandwidth request message through the network from source to destination. At each intermediate node, this bandwidth request is examined and the node determines how much of the requested traffic level it will be able to support at a time in the future of one round-trip interval hence, and this node either grants the request or marks down the request to a level that it can support, then passes it on. When the request reaches the destination, it is returned along the same path to the source, and the source then employs the marked-down allocation to select the rate used to send the burst of data. The allocation for this source node remains in effect for a limited time, depending upon the amount of data to be sent in the burst, then returns to a "residual" level.