Interpretations

Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretations for IEEE Std 802.1AX™-2008 IEEE Standard for Local and Metropolitan Area Networks - Link Aggregation

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Interpretation Request #1
Clause:
5.3
In the above mentioned Standard and clause, what does maximizing link aggregation mean? Does it refer to the following scenario?

  • There are two peers connected to a device and LACP is configured between the device and peer1, say with 4 links.
  • If the links are dynamically removed from peer1 one by one and attached to peer2, say 3 links, LACP should aggregate the device and peer2.

Thus, the peer with more number of links to the 16 March 2010 device should have an active LACP group and the other peer session with say one link should get deactivated?

Interpretation Response
The interpretation request raises two questions:

  1. What is meant by "maximizing link aggregation"? and
  2. What is the relationship between link aggregation groups between a system and two different peers?

The note in 5.3 regarding maximizing link aggregation means that if a link aggregation group is configured between a system and a peer then a link between the system and that peer will automatically be added to the link aggregation group if it is useable (unless explicitly prohibited by management). This tends to maximize the set of links in the link aggregation group to that peer.

There is no relationship between link aggregation groups to different peers. That is, the addition of a link to peer 2 has no impact on the link aggregation group between the system and peer 1. Similarly, the number of links in an aggregation group to peer 2 has no impact on the operation of a link aggregation group to peer 1.