Enterasys Networks D-Series - Manual (Page 164)

Link Aggregation Control Protocol (LACP)
6-38 Port Configuration
is, will block redundant paths). For information about building static aggregations, refer to set
lacp static (
page 6‐42 ).
Each D‐Series module provides six virtual link aggregator ports, which are designated in the CLI
as lag.0.1 through lag.0.6. Each LAG can have up to eight associated physical ports. Once
underlying physical ports (for example, 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.x.x port designation. LACP
determines which underlying physical ports are capable of aggregating by comparing operational
keys. Aggregator ports allow only underlying ports with keys matching theirs to join their LAG.
LACP uses a system priority value to build a LAG ID, which determines aggregation precedence.
If there are two partner devices competing for the same aggregator, LACP compares the LAG IDs
for each grouping of ports. The LAG with the lower LAG ID is given precedence and will be
allowed to use the aggregator.
There are a few cases in which ports will not aggregate:
• An underlying physical port is attached to another port on this same switch (loopback).
• There is no available aggregator for two or more ports with the same LAG ID. This can
happen if there are simply no available aggregators, or if none of the aggregators have a
matching admin key and system priority.
• 802.1x authentication is enabled using the set eapol command ( page 17‐19 ) and ports that
would otherwise aggregate are not 802.1X authorized.
The LACP implementation on the D‐Series device will allow up to eight physical ports into a
LAG. The device with the lowest LAG ID determines which underlying physical ports are allowed
into a LAG based on the ports’ LAG port priority. Ports with the lowest LAG port priority values
are allowed into the LAG and all other speed groupings go into a standby state.
When an existing dynamically created LAG is reduced to one port, the D‐Series removes the LAG
from its VLAN and adds the remaining underlying port to the VLAN. For this reason, you should
ensure that the LAG and all the ports in the LAG are assigned to the egress list of the desired
VLAN. Otherwise, when the LAG is removed, the remaining port may be assigned to the wrong
VLAN. The other option is to enable the singleportlag feature as described in “
set lacp
singleportlag ” on page 6‐44.
Commands
Note: To aggregate, underlying physical ports must be running in full duplex mode and must be of
the same operating speed.
For information about... Refer to page...
show lacp 6-39
set lacp 6-40
set lacp asyspri 6-41
set lacp aadminkey 6-41
clear lacp 6-42
set lacp static 6-42
clear lacp static 6-43
set lacp singleportlag 6-44