Chapter 4: Ports and Trunking
When the system is initialized, all ports by default are in LACP off mode and are assigned unique admin keys. To make a group of ports aggregatable, you assign them all the same admin key. You must set the port’s LACP mode to active to activate LACP negotiation. You can set other port’s LACP mode to passive, to reduce the amount of LACPDU traffic at the initial
Use the following command to check whether the ports are trunked:
ex2500# show lacp information
LACP Configuration Guidelines
Consider the following guidelines when you configure LACP trunks:
On static trunks, configuration parameters (such as settings for VLAN membership, ACLs, and QoS) are applied per port. When an LACP trunk group is formed, these parameters are configured for the trunk ID, which overrides the
The range of potential LACP trunk IDs is 13 through 36.
When an LACP trunk forms, the trunk ID is determined by the lowest port number in the trunk. For example, if the lowest port number is 1, then the LACP trunk ID is 13.
The LACP trunk ID can change if the link is lost on the lowest port in the group. When the trunk ID changes,
Configuring LACP
Use the following procedure to configure LACP for port 7 and port 8 to participate in link aggregation.
1.Define the admin key on port 7. Only ports with the same admin key can form an LACP trunk group.
ex2500(config)# interface port
2.Set the LACP mode.
Optionally Reducing LACP Timeout
The LACP timeout period is the number of seconds that elapse before the switch invalidates LACP data from a remote partner. The default LACP timeout value is long (90 seconds).
Link Aggregation Control Protocol 49
