Each ELSM-enabled port exists in one of the following states:
Up—Indicates a healthy remote system and this port is receiving Hello+ messages from its peer.
If an ELSM-enabled port enters the Up state, the up timer begins. Each time the port receives a Hello+ message from its peer, the up timer restarts and the port remains in the Up state. The up timer is 6 * hello timer, which by default is 6 seconds.
Down—Indicates that the port is down, blocked, or has not received Hello+ messages from its peer.
If an ELSM-enabled port does not receive a hello message from its peer before the up timer expires, the port transitions to the Down state. When ELSM is down, data packets are neither forwarded nor transmitted out of that port.
Down-Wait—Indicates a transitional state.
If the port enters the Down state and later receives a Hello+ message from its peer, the port enters the Down-Wait state. If the number of Hello+ messages received is greater than or equal to the hold threshold (by default, two messages), the port transitions to the Up state. If the number of Hello+ messages received is less than the hold threshold, the port enters the Down state.
Down-Stuck—Indicates that the port is down and requires user intervention.
If the port repeatedly flaps between the Up and Down states, the port enters the Down-Stuck state. Depending on your configuration, there are two ways for a port to transition out of this state:
By default, automatic restart is enabled, and the port automatically transitions out of this state. For more information, see the enable elsm ports port_list auto-restart command.
Note
If you reboot the peer switch, its ELSM-enabled peer port may enter the Down-Stuck state. If this occurs, clear the stuck state using one of the following commands:For information about displaying ELSM port states, see Displaying ELSM Information.