Exploratory linktrace operations in a computer network

Patent metadata

Field	Value
Publication number	US-10084684-B2
Application number	US-201715654054-A
Country	US
Kind code	B2
Filing date	Jul 19, 2017
Priority date	Jan 21, 2009
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

In one embodiment, an exploratory linktrace is initiated from an initiating network device with an exploratory linktrace message (ELM) having a target address. Each network device receiving the ELM may then propagate the ELM on a plurality of its ports to a plurality of downstream network devices based on the target address. In addition, each receiving network device returns an exploratory linktrace reply (ELR) for each of the plurality of ports, where each ELR is returned according to one or more mechanisms to mitigate stormed replies to the initiating network device.

First claim

What is claimed is:

1. A network device, comprising:
a processor; and
a memory having computer-executable instructions that, when executed on the processor, causes the processor to perform operations comprising:
receive a unicast data message directed to the network device, the data message encapsulating an exploratory linktrace message (ELM) from an initiating network device;
decapsulate the ELM from the data message;
propagate the ELM on a plurality of ports of the network device;
obtain an exploratory linktrace reply (ELR) for each of the plurality of ports of the network device to produce a plurality of ELRs; and
send the plurality of ELRs to the initiating network device.

2. The network device of claim 1 , wherein the plurality of ELRs are sent to the initiating network device within a maximum response time.

3. The network device of claim 2 , wherein the maximum response time is based on a number of egress ports on the network device.

4. The network device of claim 2 , wherein the processor is further configured to:
inform the initiating network device of a maximum response time for a next downstream network device to respond with an ELR.

5. The network device of claim 2 , wherein the ELM comprises a delay indication field including at least one of a maximum response time, a technique for computing the maximum response time, or a maximum number of ELRs.

Assignees

• Cisco Tech Inc

Inventors

• Finn Norman W
• Salam Samer
• Monaghan John
• Mcdade Iain
• Ball David Alexander
• Chatterjee Simon

Classifications

• H04L43/10

  Active monitoring, e.g. heartbeat, ping or trace-route · CPC title

• H04L45/26

  Route discovery packet · CPC title

• H04L41/12

  Discovery or management of network topologies · CPC title

• H04L45/02 Primary

  Topology update or discovery · CPC title

• H04L12/462 Primary

  LAN interconnection over a bridge based backbone · CPC title