FTOS Configuration Guide for the C-Series - Force10 Networks

Important Points to Remember
• LACP enables you to add members to a port channel (LAG) as long as it has no static members.
Conversely, if the LAG already contains a statically defined member (channel-member command),
the port-channel mode command is not permitted.
• A static LAG cannot be created if a dynamic LAG using the selected number already exists.
• No dual membership in static and dynamic LAGs:
• If a physical interface is a part of a static LAG, then the command port-channel-protocol lacp
will be rejected on that interface.
• If a physical interface is a part of a dynamic LAG, it cannot be added as a member of a static
LAG. The command channel-member gigabitethernet x/y will be rejected in the static LAG
interface for that physical interface.
• A dynamic LAG can be created with any type of configuration.
• There is a difference between the shutdown and no interface port-channel:
— The shutdown command on LAG “xyz” disables the LAG and retains the user commands.
However, the system does not allow the channel number “xyz” to be statically created.
— The command no interface port-channel channel-number deletes the specified LAG, including a
dynamically created LAG. This command causes all LACP-specific commands on the member
interfaces to be removed. The interfaces are restored to a state that is ready to be configured.
Note: There will be no configuration on the interface since that condition is required for an
interface to be part of a LAG.
• Link dampening can be configured on individual members of a LAG. See Link Dampening on
page 276 for more information.
• LACP cannot add an interface to a LAG if one of the LAG members is shut down on the remote
interface. If a remote LAG member is shut down, Message 17 appears on the local system when you
attempt to add a member. In this case, enable all members of the LAG on the remote system, and then
add any new members on the local system.
Message 17 LACP Remote Port Down Error Message
% Error: This port property does not match with other LAG member.
LACP modes
FTOS provides the following three modes for configuration of LACP:
• Off—In this state, an interface is not capable of being part of a dynamic LAG. LACP does not run on
any port that is configured to be in this state.
• Active—In this state, the interface is said to be in the “active negotiating state.” LACP runs on any
link that is configured to be in this state. A port in Active state also automatically initiates negotiations
with other ports by initiating LACP packets.
• Passive—In this state, the interface is not in an active negotiating state, but LACP will run on the link.
A port in Passive state also responds to negotiation requests (from ports in Active state). Ports in
Passive state respond to LACP packets.
210 Link Aggregation Control Protocol (LACP)