Specifications

Link Aggregation Control Protocol (LACP)
LACP Terminology
3-48 SecureStack A2 Configuration Guide
• Uses information from the partner device’s link aggregation control entity to decide whether to
aggregate ports.
The operation of LACP involves the following activities:
• Checking that candidate links can actually be aggregated.
• Controlling the addition of a link to a LAG, and the creation of the group if necessary.
• Monitoring the status of aggregated links to ensure that the aggregation is still valid.
• Removing a link from a LAG if its membership is no longer valid, and removing the group if it
no longer has any member links.
In order to allow LACP to determine whether a set of links connect to the same device, and to
determine whether those links are compatible from the point of view of aggregation, it is necessary
to be able to establish the following:
• A globally unique identifier for each device that participates in link aggregation.
• A means of identifying the set of capabilities associated with each port and with each aggregator,
as understood by a given device.
• A means of identifying a LAG and its associated aggregator.
3.5.2 LACP Terminology
Table 3-3 defines key terminology used in LACP configuration.
Table 3-3 LACP Terms and Definitions
Term Definition
Aggregator Virtual port that controls link aggregation for underlying physical ports. Each
SecureStack A2 unit provides 6 aggregator ports, which are designated in
the CLI as lag.0.1 through lag.0.6.
LAG Link Aggregation Group. Once underlying physical ports (that is, fe.x.x or
ge.x.x) are associated with an aggregator port, the resulting aggregation will
be represented as one LAG with a lag.0.x port designation.
NOTE: SecureStack A2 LAGs can have up to 4 associated physical
ports.
LACPDU Link Aggregation Control Protocol Data Unit. The protocol exchanges
aggregation state/mode information by way of a port’s actor and partner
operational states. LACPDUs sent by the first party (the actor) convey to the
second party (the actor’s protocol partner) what the actor knows, both about
its own state and that of its partner.