# US 2014/0192632 A1 · Loop avoidance for event-driven virtual link aggregation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192632 A1 - Document ID: US20140192632A1 - Status: Published application - Kind: A1 - Application number: 14/089,660 - Filed: 2013-11-25 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Tamanna Z. Sait; Venkatesan Selvaraj; Shoou J. Yiu; Yi Xia - Web page: https://patentgrep.com/patent/US20140192632A1 ## CPC - H04L 45/18: Loop-free operations - H04L 41/0668: by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L 47/41: by acting on aggregated flows or links - 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 Embodiments of the invention relate to virtual link aggregation. One embodiment includes forming one or more virtual links using physical links connecting a first networking element, a second networking element and a third networking element. A first trigger status indication is used for blocking network traffic for avoiding traffic loops occurring over the one or more virtual links. ## Claims ### Claim 1 A method for virtual link aggregation comprising: coupling a first networking element to a second networking element using a first link; coupling the first networking element to a third networking element using a second link; coupling the second networking element to the third networking element using a third link; establishing a first virtual link between the third networking element and each one of the first networking element and the second networking element; managing networking traffic from the first networking element based at least in part on a first trigger status; and determining the first trigger status based at least in part on establishing of the first virtual link, wherein the first trigger status is set to enabled prior to the establishing of the first virtual link, and the first trigger status is set to disabled after the establishing of the first virtual link. ### Claim 2 (depends on 1) The method of claim 1, wherein at least a portion of the networking traffic from the first networking element is blocked when the first trigger status is set to enabled, and at least a portion of the networking traffic of the first networking element flows when the first trigger status is set to disabled, and the first networking element includes a first plurality of networking ports, the second networking element includes a second plurality of networking ports, and the third networking element includes a third plurality of networking ports. ### Claim 3 (depends on 2) The method of claim 2, wherein the first virtual link is established using the third link and the second link, wherein the first networking element and the second networking element comprise aggregation switches, and the third networking element comprises an access switch. ### Claim 4 (depends on 3) The method of claim 3, further comprising: managing networking traffic for the second networking element based at least in part on a second trigger status, wherein at least a portion of the networking traffic from the second networking element is blocked when the second trigger status is set to enabled, and at least a portion of the networking traffic from the second networking element flows when the second trigger status is set to disabled. ### Claim 5 (depends on 4) The method of claim 4, further comprising: determining the second trigger status based at least in part on the establishing of the first virtual link, wherein prior to the establishing of the first virtual link the second trigger status is set to disabled, and after the establishing of the first virtual link the second trigger status is set to enabled. ### Claim 6 (depends on 5) The method of claim 5, further comprising: sending a first query message from the first networking element to the second networking element using the first link, wherein the establishing of the first virtual link is based at least in part on the first networking element receiving a response to the first query message from the second networking element; and activating a first event, wherein the establishing of the first virtual link is based on the first networking element receiving a response to the first query message from the second networking element prior to the activation of the first event, wherein the first plurality of networking ports are enabled upon detecting the activation of the first event. ### Claim 7 (depends on 6) The method of claim 6, further comprising: initiating a health check process based on the activation of the first event; disabling the first plurality of networking ports upon the health check process indicating that the second networking element is active; and enabling the first plurality of networking ports upon the health check process indicating that the second networking element is inactive. ### Claim 8 (depends on 7) The method of claim 7, wherein the activating of the first event is based at least in part on one of a first programmable delay value and receiving a response to the first query message from the second networking element. ### Claim 9 A method comprising: forming one or more virtual links using physical links connecting a first networking element, a second networking element and a third networking element; and using a first trigger status indication for blocking network traffic for avoiding traffic loops occurring over the one or more virtual links. ### Claim 10 (depends on 9) The method of claim 9, further comprising: coupling the first networking element to the second networking element using a first link; coupling the first networking element to the third networking element using a second link; coupling the second networking element to the third networking element using a third link; establishing a first virtual link between the third networking element and each one of the first networking element and the second networking element; managing networking traffic from the first networking element based at least in part on the first trigger status; and determining the first trigger status based at least in part on establishing of the first virtual link, wherein the first trigger status is set to enabled prior to the establishing of the first virtual link, and the first trigger status is set to disabled after the establishing of the first virtual link, wherein at least a portion of the networking traffic from the first networking element is blocked when the first trigger status is set to enabled, and at least a portion of the networking traffic of the first networking element flows when the first trigger status is set to disabled, the first networking element includes a first plurality of networking ports, the second networking element includes a second plurality of networking ports, and the third networking element includes a third plurality of networking ports, and the first virtual link is established using the third link and the second link, wherein the first networking element and the second networking element comprise aggregation switches, and the third networking element comprises an access switch.