# US 2018/0324089 A1 · Spanning tree protocol enabled n-node link aggregation system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324089 A1 - Document ID: US20180324089A1 - Status: Published application - Kind: A1 - Application number: 15/586,088 - Filed: 2017-05-03 - Published: 2018-11-08 - Earliest claimed: 2017-05-03 - Assignees: Dell Products L.P. - Applicants: Dell Products L.P. - Inventors: Saye Balasubramaniam Subramanian; Senthil Nathan Muthukaruppan - Web page: https://patentgrep.com/patent/US20180324089A1 ## CPC - H04L 45/02: Topology update or discovery - H04L 45/245: {Link aggregation, e.g. trunking} - H04L 45/48: Routing tree calculation - H04L 45/586: of virtual routers - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A spanning tree enabled n-node VLT system includes the STP running on VLT node devices that include a first VLT node device coupled to a networking device by a LAG and designated as a root bridge via the STP. A second VLT node device coupled to the networking device is part of the LAG. ICLs couple the second VLT node device to the first VLT node device. An enhanced STP engine running on the each of the VLT node devices determines that the STP has designated a first port providing one of the ICLs as a first root port, and a second port providing one of the ICLs as an alternate port. In response, the enhanced STP engine redesignates the second port as a second root port. ## Claims ### Claim 1 A spanning tree enabled n-node link aggregation system, comprising: a networking device; a plurality of link aggregation node devices, wherein the spanning tree protocol runs on each of the plurality of link aggregation node devices, and wherein the plurality of link aggregation node devices include: a first link aggregation node device that is coupled to the networking device by at least one first link that is part of a Link Aggregation Group (LAG), wherein the first link aggregation node device has been designated as a root bridge via the spanning tree protocol; and a second link aggregation node device that is coupled to the networking device by at least one second link that is part of the LAG; a plurality of Inter-Chassis Links (ICLs) coupled to the second link aggregation node device; and an enhanced spanning tree protocol engine running on the each of the plurality of link aggregation node devices, wherein the enhanced spanning tree protocol engine is configured to: determine that a first port that is part of one of the plurality of ICLs has been designated as a first root port via the spanning tree protocol; determine that a second port that is part of one of the plurality of ICLs has been designated as an alternate port via the spanning tree protocol; and redesignate, in response to the first port being part of one of the plurality of ICLs and designated as the first root port and the second port being part of one of the plurality of ICLs and designated as the alternate port, the second port as a second root port. ### Claim 2 (depends on 1) The system of claim 1, wherein the plurality of link aggregation node devices are part of a Virtual Link Trunking fabric. ### Claim 3 (depends on 1) The system of claim 1, wherein the enhanced spanning tree protocol engine is configured to: ensure that Media Access Control (MAC) address flushing is not invoked on any ports that are part of any of the plurality of ICLs. ### Claim 4 (depends on 1) The system of claim 1, wherein the enhanced spanning tree protocol engine is configured to: receive a topology change notification; and block, in response to the second port having been designated as the alternate port via the spanning tree protocol, the transmission of the topology change notification on the ICL that includes the second port. ### Claim 5 (depends on 1) The system of claim 1, wherein the enhanced spanning tree protocol engine is configured to: ensure that the spanning tree protocol running on each of the plurality of link aggregation node devices is aware of the LAG. ### Claim 6 (depends on 1) The system of claim 1, wherein the enhanced spanning tree protocol engine is configured to: determine that at least one of the plurality of link aggregation node devices does not include a local port-channel for the LAG and, in response, create a virtual port in that link aggregation node device for the LAG. ### Claim 7 (depends on 6) The system of claim 6, wherein the enhanced spanning tree protocol engine is configured to: transmit a control message via the virtual port. ### Claim 8 An Information Handling System (IHS), comprising: a plurality of Inter-Chassis Links (ICLs) that couple a plurality of ICL ports to a first of a plurality of link aggregation node devices that has been designated as a root bridge by via the spanning tree protocol running on each of the plurality of link aggregation node devices; a Link Aggregation Group (LAG) that includes a plurality of LAG ports and that is coupled to a networking device; a processing system that is coupled to the plurality of ICL ports and the plurality of LAG ports, and a memory system that is coupled to the processing system and that includes instructions that, when executed by the processing system, cause the processing system to provide an enhanced spanning tree protocol engine that is configured to: determine that a first ICL port of the plurality of ICL ports has been designated as a first root port via the spanning tree protocol; determine that a second ICL port of the plurality of ICL ports has been designated as an alternate port via the spanning tree protocol; and redesignate, in response to the first ICL port being designated as the first root port and the second ICL port being designated as the alternate port, the second port as a second root port. ### Claim 9 (depends on 8) The IHS of claim 8, wherein the plurality of link aggregation node devices are part of a Virtual Link Trunking fabric. ### Claim 10 (depends on 8) The IHS of claim 8, wherein the enhanced spanning tree protocol engine is configured to: ensure that Media Access Control (MAC) address flushing is not invoked on any of the plurality of ICL ports. ### Claim 11 (depends on 8) The IHS of claim 8, wherein the enhanced spanning tree protocol engine is configured to: receive a topology change notification; and block, in response to the second port having been designated as the alternate port via the spanning tree protocol, the transmission of the topology change notification on the ICL that includes the second port. ### Claim 12 (depends on 8) The IHS of claim 8, wherein the enhanced spanning tree protocol engine is configured to: ensure that the spanning tree protocol running on each of the plurality of link aggregation node devices is aware of the LAG. ### Claim 13 (depends on 8) The IHS of claim 8, wherein the enhanced spanning tree protocol engine is configured to: determine that at least one of the plurality of link aggregation node devices does not include a local port-channel for the LAG and, in response, create a virtual port in that link aggregation node device for the LAG; and transmit a control message via the virtual port. ### Claim 14 A method for enabling the spanning tree protocol in an n-node link aggregation system. comprising: coupling, by a link aggregation engine, a plurality of ICL ports to a first of a plurality of link aggregation node devices via a plurality of Inter-Chassis Links (ICL); aggregating, by the link aggregation engine, at least one Link Aggregation Group (LAG) port to provide a LAG; designating, via the spanning tree protocol running on each of a plurality of link aggregation node devices, the first of the plurality of link aggregation node devices as a root bridge; determining, by an enhanced spanning tree protocol engine, that a first ICL port of the plurality of ICL ports has been designated as a first root port via the spanning tree protocol; determining, by the enhanced spanning tree protocol engine, that a second ICL port of the plurality of ICL ports has been designated as an alternate port via the spanning tree protocol; and redesignating, by the enhanced spanning tree protocol engine in response to the first ICL port being designated as the first root port and the second ICL port being designated as the alternate port, the second port as a second root port. ### Claim 15 (depends on 14) The method of claim 14, wherein plurality of link aggregation node devices are part of a Virtual Link Trunking fabric. ### Claim 16 (depends on 14) The method of claim 14, further comprising: ensuring, by the enhanced spanning tree protocol engine, that Media Access Control (MAC) address flushing is not invoked on any of the plurality of ICL ports. ### Claim 17 (depends on 14) The method of claim 14, further comprising: receiving, by the enhanced spanning tree protocol engine, a topology change notification; and blocking, by the enhanced spanning tree protocol engine in response to the second port having been designated as the alternate port via the spanning tree protocol, the transmission or receipt of the topology change notification on the ICL that includes the second port. ### Claim 18 (depends on 14) The method of claim 14, further comprising: ensuring, by the enhanced spanning tree protocol engine, that the spanning tree protocol running on each of the plurality of link aggregation node devices is aware of the LAG. ### Claim 19 (depends on 14) The method of claim 14, further comprising: determining, by the enhanced spanning tree protocol engine, that at least one of the plurality of link aggregation node devices does not include a local port-channel for the LAG and, in response, creating a virtual port in that link aggregation node device for the LAG. ### Claim 20 (depends on 19) The method of claim 19, further comprising: transmitting, by the enhanced spanning tree protocol engine, a control message via the virtual port.