Abstract: In one embodiment, a list of border node next hop options is maintained in a memory. The list of border node next hop options includes one or more of border nodes that may be utilized to reach one or more prefixes. An index value is associated with each border node of the list of border node next hop options. A list of labels is also maintained in the memory. The index value of each border node is associated with a corresponding label for a path to reach that border node. When a change to the one or more border nodes is detected, the list of border node next hop options is updated to remove a border node. However, a label for the path to reach the border node is maintained in the list of labels for at least a period of time.

Abstract: In one embodiment, an apparatus generally comprises one or more input interfaces for receiving a plurality of flows, a plurality of output interfaces, and a processor operable to identify large flows and select one of the output interfaces for each of the large flows to load-balance the large flows over the output interfaces. The apparatus further includes memory for storing a list of the large flows, a pinning mechanism for pinning the large flows to the selected interfaces, and a load-balance mechanism for selecting one of the output interfaces for each of the remaining flows. A method for local placement of large flows to assist in load-balancing is also disclosed.

Abstract: A method is disclosed for dynamically creating encapsulation and decapsulation chains and segmenting the packet-forwarding plane. A distributed router may comprise multiple cards, each exposing a subset of the router's physical interfaces. Some physical interfaces may be configured to send/receive only certain types and destinations of data packets. Some cards might not expose any physical interfaces configured to send/receive a particular type and destination of packet, making encapsulation and/or decapsulation chains for virtual interfaces that process data packets of the particular type useless on those cards. Therefore, instead of always creating both encapsulation and decapsulation chains for a virtual interface on a card, an aspect of the method dynamically determines which of the encapsulation and decapsulation chains are useful for a virtual interface on that card, and creates only those chains that are useful on that card.

Abstract: In one embodiment, a list of border node next hop options is maintained in a memory. The list of border node next hop options includes one or more of border nodes that may be utilized to reach one or more prefixes. An index value is associated with each border node of the list of border node next hop options. A list of labels is also maintained in the memory. The index value of each border node is associated with a corresponding label for a path to reach that border node. When a change to the one or more border nodes is detected, the list of border node next hop options is updated to remove a border node. However, a label for the path to reach the border node is maintained in the list of labels for at least a period of time.

Abstract: A scheduling method and system for a multi-level class hierarchy are disclosed. The hierarchy includes a root node linked to at least two groups. One of the groups has priority over the other of the groups and comprises at least one high priority queue and at least one low priority queue. The method includes receiving traffic at the root node, directing traffic received at the root node to one of the groups, and directing traffic received at the priority group to one of the high priority and low priority queues. Packets are accepted at the high priority queue or the low priority queue if a specified rate is not exceeded at the high and low priority queues and at least some packets are dropped at the low priority queue if the specified rate is exceeded at the high and low priority queues.

Abstract: In one embodiment, one or more virtual private network (VPN) prefixes may be grouped at a network node into sets having shared network border node next-hop options, where each border node has a defined index value associated therewith. Also, a list of VPN labels associated with each VPN prefix may be maintained by the network node, where each VPN label is associated with a border node of a particular set by a corresponding index value. Further, the network node may determine a particular border node for traffic to be forwarded, along with the defined index value. The network node may then apply the index value to select an associated VPN label, and may affix the selected VPN label to the traffic for forwarding.

Abstract: In one embodiment, one or more virtual private network (VPN) prefixes may be grouped at a network node into sets having shared network border node next-hop options, where each border node has a defined index value associated therewith. Also, a list of VPN labels associated with each VPN prefix may be maintained by the network node, where each VPN label is associated with a border node of a particular set by a corresponding index value. Further, the network node may determine a particular border node for traffic to be forwarded, along with the defined index value. The network node may then apply the index value to select an associated VPN label, and may affix the selected VPN label to the traffic for forwarding.

Abstract: In one embodiment, an apparatus generally comprises one or more input interfaces for receiving a plurality of flows, a plurality of output interfaces, and a processor operable to identify large flows and select one of the output interfaces for each of the large flows to load-balance the large flows over the output interfaces. The apparatus further includes memory for storing a list of the large flows, a pinning mechanism for pinning the large flows to the selected interfaces, and a load-balance mechanism for selecting one of the output interfaces for each of the remaining flows. A method for local placement of large flows to assist in load-balancing is also disclosed.

Abstract: A method, performed in a network packet routing element, comprises establishing a forwarding information base (FIB) lacking a hierarchical data structure but in which one or more dependent FIB entries are associated with a parent FIB entry; establishing a plurality of strict priority queues, each having an associated priority; receiving a change to the parent FIB entry; for each of the dependent FIB entries, selecting one of the queues and enqueuing the dependent FIB entries in the selected queues for re-resolution; dequeuing the dependent FIB entries for re-resolution, according to a priority order of the queues.

Abstract: A Fast Reroute implementation suitable for use in a label switched router. Reroute from protected tunnels to backup tunnels may be achieved in constant time irrespective of the numbers of protected forwarding equivalence classes and protected tunnels.

Abstract: A method, performed in a network packet routing element, comprising establishing a forwarding information base (FIB) lacking a hierarchical data structure but wherein one or more dependent FIB entries are associated with a parent FIB entry; establishing a plurality of strict priority queues, wherein each of the queues has an associated priority; receiving a change to the parent FIB entry; for each of the dependent FIB entries, selecting one of the queues and enqueuing the dependent FIB entries in the selected queues for re-resolution; dequeuing the dependent FIB entries for re-resolution, according to a priority order of the queues.

Abstract: Stored in the leaf nodes of a data structure that can be used for identifying the longest prefix matching an address are corresponding values from multiple forwarding information bases. A single common address lookup data structure (e.g., a tree, trie, etc.) can be used, and a leaf node can contain information from multiple forwarding information bases. If lookup operations are performed for a single address in multiple forwarding information bases, the single common address lookup data structure may only need to be traversed once. For example, the forwarding information for another forwarding information base may be stored in the same leaf, further down in the data structure requiring traversal from the current position, or above requiring traversal from the root of the lookup data structure. Information can be stored in the leaf node to indicate which traversal option is appropriate for a particular forwarding information base.

Abstract: A scheduling method and system for a multi-level class hierarchy are disclosed. The hierarchy includes a root node linked to at least two groups. One of the groups has priority over the other of the groups and comprises at least one high priority queue and at least one low priority queue. The method includes receiving traffic at the root node, directing traffic received at the root node to one of the groups, and directing traffic received at the priority group to one of the high priority and low priority queues. Packets are accepted at the high priority queue or the low priority queue if a specified rate is not exceeded at the high and low priority queues and at least some packets are dropped at the low priority queue if the specified rate is exceeded at the high and low priority queues.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms, for identifying admission control policies and enforcement of these admission control policies on packets destined for a route processor. A typical routing device includes: a route processor, a forwarding lookup mechanism for identifying packets destined for the route processor; a lookup mechanism for identifying admission control parameters for packets destined for the route processor; and an admission control enforcement mechanism for enforcing the identified admission control policy parameters for the packets.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms, for a route processor adjusting admission control policies for packets destined for the route processor and enforced on line cards. Individual line cards can identify offending packet flows that pass through them. However, for example, it is possible that an attack on the route processor might comprise packets being forwarded to the route processor from different line cards, with these packets belonging to a same or different packet flow. By monitoring and identifying offending packet flows, the route processor can inform at least the line cards corresponding to these offending packet flows in order to adjust their corresponding admission control policies to combat such an attack, while typically allowing legitimate traffic to continue to flow at the desired rate to the route processor.

Abstract: A Fast Reroute implementation suitable for use in a label switched router. Reroute from protected tunnels to backup tunnels may be achieved in constant time irrespective of the numbers of protected forwarding equivalence classes and protected tunnels.

Abstract: Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, mechanisms, and means for maintaining and using a data structure identifying for multiple addresses the reverse path forwarding information for a common intermediate node. A data structure includes an address lookup data structure for identifying leaf nodes of multiple leaf nodes corresponding to matching addresses. Each of the multiple leaf nodes includes a reverse path forwarding indirection link to a corresponding sub-data structure indicating reverse path forwarding information. Each of a particular set of leaf nodes having a same intermediate reachability node in a network includes a particular indirection link to a same particular sub-data structure indicating reverse path forwarding information. The intermediate reachability node may or may not be a gateway node to a different intranet.

Abstract: A method is disclosed for dynamically creating encapsulation and decapsulation chains and segmenting the packet-forwarding plane. A distributed router may comprise multiple cards, each exposing a subset of the router's physical interfaces. Some physical interfaces may be configured to send/receive only certain types and destinations of data packets. Some cards might not expose any physical interfaces configured to send/receive a particular type and destination of packet, making encapsulation and/or decapsulation chains for virtual interfaces that process data packets of the particular type useless on those cards. Therefore, instead of always creating both encapsulation and decapsulation chains for a virtual interface on a card, an aspect of the method dynamically determines which of the encapsulation and decapsulation chains are useful for a virtual interface on that card, and creates only those chains that are useful on that card.