Embodiments of this application provide a packet transmission method, and a communications apparatus and system. The method includes: generating a packet based on address information of forwarding nodes on a packet forwarding path, where the packet includes a first indication field, the first indication field is used to indicate a compressed first element and a compressed second element, the first element and the second element are address information of different forwarding nodes, and different address compression manners are used for the first element and the second element; and sending the packet.

A system and method for building a data structure for determining if multiple routing or forwarding tables yield the same or different forwarding behaviors. VeriTable uses a single tree/trie traversal to quickly check if multiple forwarding tables are forwarding equivalent, yield routing loops, or black holes. VeriTable also uses the Longest Prefix Matching rule for lookups, e.g., checking if route updates in control plane are consistent with the ones in forwarding plane. VeriTable can be applied to network-wide abnormality diagnosis of network problems, such as scalable and efficient forwarding loop detection and avoidance in the data plane of a network. In addition, VeriTable can be extended to handle incremental updates applied to the forwarding tables in a network.

A router configured as an autonomous system border router (ASBR) in a local autonomous system (AS), includes: (1) a control component for communicating and computing routing information, the control component running a Border Gateway Protocol (BGP) and peering with at least one BGP peer device in an outside autonomous system (AS) different from the local AS; and (2) a forwarding component for forwarding packets using forwarding information derived from the routing information computed by the control component, wherein the control component (i) receives reachability information for an external prefix corresponding to a device outside the local AS, and (ii) associates the external prefix, as a BGP next hop (B_NH), an abstract next hop (ANH) that identifies a set of BGP (eBGP) sessions that contains at least one eBGP session over which given external prefix has been learned, each of the at least one eBGP sessions being between the ASBR and a BGP peer device in an AS outside the AS, wherein the device located outside the local AS is reachable via the BGP peer device.

A router configured as an autonomous system border router (ASBR) in a local autonomous system (AS), includes: (1) a control component for communicating and computing routing information, the control component running a Border Gateway Protocol (BGP) and peering with at least one BGP peer device in an outside autonomous system (AS) different from the local AS; and (2) a forwarding component for forwarding packets using forwarding information derived from the routing information computed by the control component, wherein the control component (i) receives reachability information for an external prefix corresponding to a device outside the local AS, and (ii) associates the external prefix, as a BGP next hop (B_NH), an abstract next hop (ANH) that identifies a set of BGP (eBGP) sessions that contains at least one eBGP session over which given external prefix has been learned, each of the at least one eBGP sessions being between the ASBR and a BGP peer device in an AS outside the AS, wherein the device located outside the local AS is reachable via the BGP peer device.

The present disclosure provides Border Gateway Protocol route aggregation in a Clos fabric when one or more communication failures are detected. A method includes receiving a prefix component of a first aggregate route from a first next hop node, the prefix component being associated with a failed network element; announcing, to one or more neighboring nodes, the first aggregate route along with the prefix component and the first next hop node associated with the failed network element; identifying, by the one or more neighboring nodes, a second aggregate route, the second aggregate route being a shortest aggregate route that contains the first aggregate route; and generating, from the second aggregate route, one or more Chad routes to the prefix component of the first aggregate route, wherein the one or more Chad routes are associated with one or more next hop nodes that are different from the first next hop node.

In some embodiments, a method sets a threshold for utilization of a first table, wherein the utilization is based on layer 3 addresses and layer 2 addresses being stored in the first table. When a utilization of the first table does not meet the threshold, the method stores a layer 3 address in the first table. The first table uses a first type of lookup to determine a next hop address for the layer 3 addresses or the layer 2 addresses, and the first table also stores one or more layer 2 addresses. When the utilization of the first table meets the threshold, the method stores the layer 3 address in a second table where the second table uses a second type of lookup to determine the next hop address for layer 3 addresses.

In one embodiment, a method is provided. The method includes determining that a network device should use an underlay multicast group associated with an overlay multicast group for multicast traffic. The underlay multicast group carries multicast traffic for the overlay multicast group. The overlay multicast group is associated with a virtual private network. The method also includes determining an underlay multicast group address for the underlay multicast group. The overlay multicast group is associated with an overlay multicast group address. A first portion of the underlay multicast group address is a function of the overlay multicast group address. The method further includes forwarding one or more multicast packets to one or more multicast receivers via the underlay multicast group using the underlay multicast group address.

Source routing techniques include sending data across several networks, while limiting source routing overhead. For example, the source routing techniques may use a first address format to route data to nodes along a routing path that are within a first network where a source node is located, and use a second address format to route the data to a node along the routing path that is within a second, different network. The node in the second network may similarly route the data through the second network using the first address format for nodes within the second network and, if needed, route the data to a node within a third network using the second address format. This may be repeated for any number of networks to reach a destination.

Described herein are systems and methods to apply route-map configurations in a computing network. In one implementation, a routing computing system may identify a route for redistribution in a computing network and identify a longest prefix in a radix tree associated with the route. The routing computing system may further identify a highest priority route-map clause associated with the longest prefix match or any parent prefixes of the longest prefix match in the radix tree. Once identified, the computing system may perform an action associated with the highest priority route-map clause.

A network device obtains information, associated with blacklisted domains, that includes blacklisted domain identifiers, and sinkhole server identifiers associated with the blacklisted domain identifiers. The network device obtains a set of rules that specify match criteria, associated with the blacklisted domains, that include source network addresses and/or destination network addresses for comparison to packet source network addresses and/or packet destination network addresses associated with incoming packets. The set of rules specify actions to perform based on a result of comparing the match criteria and the packet source network addresses and/or the packet destination network addresses for the incoming packets. The network device receives packets, examines a packet source network address and/or a packet destination network address associated with the packets, compares the packet source network address and/or the packet destination network address to the match criteria, and performs an action based on a result of the comparison.