Configuring Lacp; Lacp Operation - Enterasys Matrix 2G4072-52 Configuration Manual

4.5

CONFIGURING LACP

CAUTION: Link aggregation configuration should only be performed by personnel who
are knowledgeable about Spanning Tree and Link Aggregation, and fully understand the
ramifications of modifications beyond device defaults. Otherwise, the proper operation
of the network could be at risk.
Using multiple links simultaneously to increase bandwidth is a desirable switch feature, which can
be accomplished if both sides agree on a set of ports that are being used as a Link Aggregation
Group (LAG). Once a LAG is formed from selected ports, problems with looping can be avoided
since the Spanning Tree can treat this LAG as a single port.
Enabled by default on Matrix devices, the Link Aggregation Control Protocol (LACP) logically
groups interfaces together to create a greater bandwidth uplink, or link aggregation, according to
the IEEE 802.3ad standard. This standard allows the switch to determine which ports are in LAGs
and configure them dynamically. Since the protocol is based on the IEEE 802.3ad specification,
any switch from any vendor that supports this standard can aggregate links automatically.
802.3ad LACP aggregations can also be run to end-users (i.e.; a server) or to a router.
NOTE: Earlier (proprietary) implementations of port aggregation referred to groups of
aggregated ports as "trunks".
4.5.1

LACP Operation

For each aggregatable port in the device, LACP:
•
Maintains configuration information (reflecting the inherent properties of the individual links as
well as those established by management) to control aggregation.
•
Exchanges configuration information with other devices to allocate the link to a Link
Aggregation Group (LAG).
NOTE: A given link is allocated to, at most, one Link Aggregation Group (LAG) at a
time. The allocation mechanism attempts to maximize aggregation, subject to
management controls.
•
Attaches the port to the aggregator used by the LAG, and detaches the port from the aggregator
when it is no longer used by the LAG.
•
Uses information from the partner device's link aggregation control entity to decide whether to
aggregate ports.
Matrix DFE-Platinum and Diamond Series Configuration Guide
Configuring LACP
LACP Operation
4-95