In-band multicast trace in IP and MPLS networks

摘要

In one embodiment, which may be implemented in either IP networks or MPLS networks, a tree of the network may be constructed at a source network device by sending only a single packet. The remaining network devices in the network replicate the packet so that a copy will reach each of the egress nodes. Along the way, identity information from each node or hop will be added to the replicated packets. As the egress nodes receive the packets, the egress nodes will each send a reply packet to the source network device. The reply packet includes a list of every hop on the path. The source network device is configured to construct a tree of the network based on the reply packets.

主权项

1. An apparatus comprising:
an interface configured to receive a packet from a router in a network, the packet initiated by a source network device; a processor configured to identify a plurality of paths from the apparatus to one or more next-hop network devices of the apparatus; the processor further configured to replicate the packet for each one of the plurality of paths when the apparatus is a forwarding node, wherein replication of the packet produces a plurality of upstream packets; the interface further configured to transmit the upstream packets to the one or more next-hop network devices of the apparatus via the paths when the apparatus is the forwarding node, the paths including a first path to a destination and a second path the destination, wherein the second path is a backup path for the first path, and wherein each of the upstream packets is a replica of the received packet appended with identity information about the forwarding node by the forwarding node; the processor further configured to extract from the received packet the identity information of forwarding nodes visited by the received packet when the apparatus is an egress node; and the interface further configured to transmit to the source network device, when the apparatus is the egress node, a reply packet comprising the extracted identity information of the forwarding nodes visited by the received packet, wherein an egress path is identifiable based on the extracted identity information, the egress path comprising a series of next-hop devices from the source network device to the egress node, the series including the router.