# US 12,003,402 B2 · Port discovery via passive internet group management protocol snooping neighbors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,402 B2 - Document ID: US12003402B2 - Status: Granted - Kind: B2 - Application number: 17/583,420 - Filed: 2022-01-25 - Published: 2022-08-04 - Granted: 2024-06-04 - Earliest claimed: 2021-02-02 - Assignees: Ruckus IP Holdings LLC - Applicants: ARRIS Enterprises LLC - Inventors: Mohammad Nasir Ahmed - Web page: https://patentgrep.com/patent/US12003402B2 ## CPC - H04L 45/02: Topology update or discovery - H04L 45/16: Multipoint routing - H04L 45/54: {Organization of routing tables} - H04L 45/74: Address processing for routing - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A computer network device (such as a switch or a router) that implement a passive snooping communication protocol is described. During operation, the computer network device may receive an instance of a message from a second computer network device in a network via a port (such as a router port) associated with a link between the computer network device and the second computer network device. Based at least in part on the received instance of the message, the computer network device may identify the port as being a type of port (such as a passive neighbor port and a non-edge port in the network), and may not forward the instance of the message to one or more additional computer network devices via one or more additional ports (such as one or more additional router ports). ## Claims ### Claim 1 A computer network device, comprising: an interface circuit; a processor; and memory configured to store program instructions, wherein, when executed by the processor, the program instructions cause the computer network device to perform operations comprising: receiving an instance of a message associated with a second computer network device in a network via a port associated with a link between the computer network device and the second computer network device; based at least in part on the received instance of the message, identifying the port as being a type of port, and not forwarding the instance of the message to one or more additional computer network devices via one or more additional ports; and providing an additional instance of the message addressed to a given additional computer network device in the one or more additional computer network devices via a given additional port in the one or more additional ports that has not already been identified as being the type of port or has not already been identified as not being the type of port. ### Claim 2 (depends on 1) The computer network device of claim 1, wherein the computer network device comprises a switch or a router. ### Claim 3 (depends on 1) The computer network device of claim 1, wherein the port and the one or more additional ports comprise a router port. ### Claim 4 (depends on 1) The computer network device of claim 1, wherein the operations comprise providing additional instances of the message addressed to the second computer networking device via the port and to the one or more additional computer network devices via the one or more additional ports. ### Claim 5 (depends on 4) The computer network device of claim 4, wherein the additional instances of the message may be provided periodically. ### Claim 6 (depends on 5) The computer network device of claim 5, wherein the additional instances of the message are provided after a predefined time interval. ### Claim 7 (depends on 6) The computer network device of claim 6, wherein, during the predefined time interval, the computer network device listens for communication associated with a host. ### Claim 8 (depends on 1) The computer network device of claim 1, wherein the type of port comprises a passive neighbor port. ### Claim 9 (depends on 1) The computer network device of claim 1, wherein the port comprises a non-edge port in the network. ### Claim 10 (depends on 1) The computer network device of claim 1, wherein the instance of the message comprises a type of message and the operations comprise, when the computer network device receives another type of message via another port associated with a host in the network, providing the other type of message addressed to the second computer network device via the port. ### Claim 11 (depends on 10) The computer network device of claim 10, wherein the operations comprise suppressing forwarding of the other type of message to the host. ### Claim 12 (depends on 10) The computer network device of claim 10, wherein the other type of message comprises an Internet group management protocol (IGMP) report or leave message. ### Claim 13 (depends on 1) The computer network device of claim 1, wherein the operations comprise: receiving an Internet group management protocol (IGMP) report or leave message; and forwarding the IGMP report or leave message via non-edge ports in the network. ### Claim 14 (depends on 1) The computer network device of claim 1, wherein the operations comprise computing a topology of the network based at least in part on received instances of the message; and wherein the topology specifies non-edge ports in the network and edge ports in the network. ### Claim 15 (depends on 1) The computer network device of claim 1, wherein the instance of the message comprises a type of message and the type of message comprises a passive neighbor message. ### Claim 16 A non-transitory computer-readable storage medium for use in conjunction with a computer network device, the computer-readable storage medium storing program instructions that, when executed by the computer network device, causes the computer network device to perform operations comprising: receiving an instance of a message associated with a second computer network device in a network via a port associated with a link between the computer network device and the second computer network device; based at least in part on the received instance of the message, identifying the port as being a type of port, and not forwarding the instance of the message to one or more additional computer network devices via one or more additional ports; and providing an additional instance of the message addressed to a given additional computer network device in the one or more additional computer network devices via a given additional port in the one or more additional ports that has not already been identified as being the type of port or has not already been identified as not being the type of port. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the port and the one or more additional ports comprise a router port. ### Claim 18 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the instance of the message comprises a type of message and the operations comprise, when the computer network device receives another type of message via another port associated with a host in the network, providing the other type of message addressed to the second computer network device via the port. ### Claim 19 A method for performing a passive snooping communication protocol, comprising: by a computer network device: receiving an instance of a message associated with a second computer network device in a network via a port associated with a link between the computer network device and the second computer network device; based at least in part on the received instance of the message, identifying the port as being a type of port, and not forwarding the instance of the message to one or more additional computer network devices via one or more additional ports; and providing an additional instance of the message addressed to a given additional computer network device in the one or more additional computer network devices via a given additional port in the one or more additional ports that has not already been identified as being the type of port or has not already been identified as not being the type of port. ### Claim 20 (depends on 19) The method of claim 19, wherein the port and the one or more additional ports comprise a router port.