Dell Force10 S4820T S4820T Configuration Guide - Page 570

www.dell.com | support.dell.com 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 Debounce Timer for more information. 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. 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. 570 | Link Aggregation Control Protocol (LACP)