Cisco Technology, Inc.

Azhar Mohammed Sayeed

James Neil Guichard

George Swallow

Thomas David Nadeau

Sam K Aldrin

Michael T Piecuch

Jean-Phillipe Vasseur

George L Swallow

Jean-Philippe Vasseur

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.

In-band multicast trace in IP and MPLS networks

A mechanism for ASBRs to identify the originating node, or router, in an LSP conversant autonomous system (AS), such as an MPLS VPN environment, maintains the identity of the originating node and successive nodes in subsequent autonomous systems along the path to the node to be pinged. The identity of the transporting nodes is stored in a stack or other object associated with the ping request (ping), such that the pinged node may employ the stored identity as a set of return path routing information. Successive ASBRs store their identity on the stack, in an ordered manner, along the path to the destination. Upon reaching the destination (ping) node, the destination node employs the identity of the first node on the stack to send the acknowledgment, or ping response. Each successive ASBR, therefore, pops (retrieves) the next node identity from the stack and redirects (sends) the ping response to the retrieved node.

System and methods for network reachability detection

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Shrewsbury, MA, United States of America

Azhar Mohammed Sayeed