Understanding How The Link Aggregation Control Protocol Works; Lacp Modes; Lacp Parameters - Cisco WS-C6506 Software Manual

Chapter 6 Configuring EtherChannel
Understanding How the Link Aggregation Control Protocol
Works
Use the information in these sections if you are configuring EtherChannel using LACP. If you are using
Note
PAgP, see the
This section contains the following descriptions:
•
•

LACP Modes

You may manually turn on channeling by setting the port channel mode to on, and you may turn off
channeling by setting the port channel mode to off.
If you want LACP to handle channeling, use the active and passive channel modes. To start automatic
EtherChannel configuration with LACP, you need to configure at least one end of the link to active mode
to initiate channeling, because ports in passive mode passively respond to initiation and never initiate
the sending of LACP packets.
Table 6-2
Table 6-2
Mode
on
off
passive
active

LACP Parameters

The parameters that are used in configuring LACP are as follows:
•
•
OL-8978-04
"Understanding How the Port Aggregation Protocol Works" section on page
LACP Modes, page 6-13
LACP Parameters, page 6-13
describes the EtherChannel modes that are available in LACP.
EtherChannel Modes Available in LACP
Description
Mode that forces the port to channel without LACP. With the on mode, a usable
EtherChannel exists only when a port group in on mode is connected to another port group
in on mode.
Mode that prevents the port from channeling.
LACP mode that places a port into a passive negotiating state in which the port responds
to LACP packets that it receives but does not initiate LACP packet negotiation. (Default)
LACP mode that places a port into an active negotiating state in which the port initiates
negotiations with other ports by sending LACP packets.
System priority
You must assign a system priority that can be specified automatically or through the CLI (see the
"Specifying the System Priority" section on page
priority is used with the switch MAC address to form the system ID and is also used during
negotiation with other systems.
Port priority

Understanding How the Link Aggregation Control Protocol Works

6-16) to each switch running LACP. The system
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
6-5.
6-13