Dell Force10 MXL Blade - Important Points to Remember; LACP Modes

288 | Link Aggregation Control Protocol (LACP)
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Important Points to Remember
• LACP allows 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, the
port-channel-protocol lacp command is 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
channel-member tengigabitethernet x/y command is rejected in the static LAG interface for that
physical interface.
• You can create a dynamic LAG with any type of configuration.
• There is a difference between the
shutdown command and the no interface port-channel command:
• 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
no interface port-channel channel-number command 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 is no configuration on the interface because that condition is required for an interface
to be part of a LAG
.
• You can configure link dampening on individual members of a LAG. For more information, refer to
MTU Size on an Interface.
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 runs 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.
FTOS supports LAGs in the following cases:
• A port in Active state can set up a port channel (LAG) with another port in Active state.
• A port in Active state can set up a LAG with another port in Passive state.
• A port in Passive state cannot set up a LAG with another port in Passive state.