Lacp Id Parameters; Channel Modes; Cisco Nexus 3000 Series Nx-Os Layer 2 Switching Configuration Guide, Release 5.0(3)U1(1 - Cisco Nexus 3000 series Configuration Manual

Understanding LACP
With LACP, just like with static port-channels, you can bundle up to 16 interfaces in a channel group.
When you delete the EtherChannel, Cisco NX-OS automatically deletes the associated channel group. All
Note
member interfaces revert to their previous configuration.
You cannot disable LACP while any LACP configurations are present.

LACP ID Parameters

LACP uses the following parameters:
• LACP system priority—Each system that runs LACP has an LACP system priority value. You can
accept the default value of 32768 for this parameter, or you can configure a value between 1 and 65535.
LACP uses the system priority with the MAC address to form the system ID and also uses the system
priority during negotiation with other devices. A higher system priority value means a lower priority.
The LACP system ID is the combination of the LACP system priority value and the MAC address.
Note
• LACP port priority—Each port configured to use LACP has an LACP port priority. You can accept the
default value of 32768 for the LACP port priority, or you can configure a value between 1 and 65535.
LACP uses the port priority with the port number to form the port identifier. LACP uses the port priority
to decide which ports should be put in standby mode when there is a limitation that prevents all compatible
ports from aggregating and which ports should be put into active mode. A higher port priority value
means a lower priority for LACP. You can configure the port priority so that specified ports have a lower
priority for LACP and are most likely to be chosen as active links, rather than hot-standby links.
• LACP administrative key—LACP automatically configures an administrative key value equal to the
channel-group number on each port configured to use LACP. The administrative key defines the ability
of a port to aggregate with other ports. A port's ability to aggregate with other ports is determined by
these factors:

Channel Modes

Individual interfaces in EtherChannels are configured with channel modes. When you run static EtherChannels,
with no protocol, the channel mode is always set to on. After you enable LACP globally on the device, you
enable LACP for each channel by setting the channel mode for each interface to active or passive. You can
configure either channel mode for individual links in the LACP channel group.
You must enable LACP globally before you can configure an interface in either the active or passive
Note
channel mode.

Cisco Nexus 3000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U1(1)

60
◦ Port physical characteristics, such as the data rate, the duplex capability, and the point-to-point or
shared medium state
◦ Configuration restrictions that you establish
Configuring EtherChannels