# US 2014/0195694 A1 · Loop avoidance for event-driven virtual link aggregation

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- Number: US 2014/0195694 A1
- Document ID: US20140195694A1
- Status: Published application
- Kind: A1
- Application number: 13/734,631
- Filed: 2013-01-04
- 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/US20140195694A1

## 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 at position 1

1-8. (canceled)

### Claim 9

A virtual aggregation link system comprising:
a first aggregation switch;
a second aggregation switch coupled to the first aggregation switch with a first link; and
at least one access switch coupled to the first aggregation switch with a second link and the second aggregation switch with a third link, the first access switch establishes a first virtual link with each one of the first aggregation switch and the second aggregation switch;
a first traffic management module coupled with the first aggregation switch, wherein the first traffic management module manages networking traffic from the first aggregation switch based at least in part on a first trigger status, and determines the first trigger status based at least in part on establishing of the first virtual link.

### Claim 10 (depends on 9)

The system of claim 9, 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 11 (depends on 10)

The system of claim 10, wherein at least a portion of the networking traffic from the first aggregation switch is blocked when the first trigger status is set to enabled, and at least a portion of the networking traffic of the first aggregation switch flows when the first trigger status is set to disabled.

### Claim 12 (depends on 11)

The system of claim 11, wherein the first aggregation switch includes a first plurality of networking ports, the second aggregation switch includes a second plurality of networking ports, and the at least one access switch includes a third plurality of networking ports, wherein the first virtual link is established using the third link and the second link.

### Claim 13 (depends on 12)

The system of claim 12, further comprising:
a second traffic management module coupled with the second aggregation switch, the second traffic management module manages networking traffic for the second aggregation switch based at least in part on a second trigger status, wherein at least a portion of the networking traffic from the second aggregation switch is blocked when the second trigger status is set to enabled, and at least a portion of the networking traffic from the second aggregation switch flows when the second trigger status is set to disabled.

### Claim 14 (depends on 13)

The system of claim 13, wherein the second traffic management module determines 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, wherein the first traffic management module sends a first query message from the first aggregation switch to the second aggregation switch 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.

### Claim 15

A non-transitory computer-useable storage medium for virtual link aggregation, the computer-useable storage medium having a computer-readable program, wherein the program upon being processed on a computer causes the computer to implement:
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 16 (depends on 15)

The program of claim 15, 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.

### Claim 17 (depends on 16)

The program of claim 16, 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; and
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 18 (depends on 17)

The program of claim 17, 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;
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;
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 at position 12

19-20. (canceled)