Displays detailed information for one or more ELSM-enabled ports.
| all | Displays detailed ELSM information for all ports. |
| port_list | Displays detailed ELSM information for one or more ports. |
N/A.
Use this command to display detailed information about the operational state of ELSM on the configured ports.
Port—The port number of the ELSM-enabled port.
Ready—Indicates that the port is enabled but there is no link.
Active—Indicates that the port is enabled and the physical link is up.
Up—Indicates that ELSM is enabled and the ELSM peer ports are up and communicating; the ELSM link state is up. In the up state, the ELSM-enabled port sends and receives hello messages from its peer.
Down—Indicates that ELSM is enabled, but the ELSM peers are not communicating; the ELSM link state is down. In the down state, ELSM transitions the peer port on this device to the down state. ELSM blocks all incoming and outgoing switching traffic and all control traffic except ELSM PDUs.
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, 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. See the command enable elsm ports auto-restart for more information.
If you disabled automatic restart, and the port enters the Down-Stuck state, you can clear the stuck state and enter the Down state by using one of the following commands:
HelloRx(+)—Specifies that the ELSM-enabled port is up and receiving Hello+ messages from its peer. The port remains in the HelloRx+ state and restarts the HelloRx timer each time it receives a Hello+ message. If the HelloRx timer expires, the hello transmit state enters HelloRX(-). The HellotRx timer is 6 * hello timer, which by default is 6 seconds.
HelloRx(-)—Specifies that the ELSM-enabled port either transitions from the initial ELSM state or is up and not receiving hello messages because there is a problem with the link or the peer is missing.
Hello time—The current value of the hello timer, which by default is 1 second. The hello timer indicates the number of seconds between consecutive hello messages.
Hold Threshold—The number of Hello+ messages required by the ELSM-enabled port to transition from the Down-Wait state to the Up state within the hold threshold.
UpTimer Threshold—The number of hello times that span without receiving Hello+ packets before a port changes its ELSM state from Up to Down.
Enabled—If an ELSM-enabled port goes down, ELSM automatically brings up the down port. This is the default behavior.
Disabled If an ELSM-enabled port goes down, the port enters and remains in the Down-Stuck state until you clear the stuck state.
For more information about automatic restart, see the command enable elsm ports auto-restart.
Sticky Threshold—Specifies the number of times a port can transition between the Up and Down states. The sticky threshold is not user-configurable and has a default value of 1. That means a port can transition only one time from the Up state to the Down state. If the port attempts a subsequent transition from the Up state to the Down state, the port enters the Down-Stuck state.
Sticky Threshold Counter—The number of times the port transitions from the Up state to the Down state.
Down Timeout—The actual waiting time (msecs or secs) before a port changes its ELSM state from Down to Up. When ELSM is enabled on a port and it is in a Down state, before it changes its ELSM state from Down to Up, it expects to receive at least a “Hold Threshold” number of Hello+ packets during the Down Timeout period after it receives the first Hello+ packet from its peer. It is equal to [Hello Time * (Hold Threshold+2)].
Up Timeout—The actual waiting time (msecs or secs) before a port changes its ELSM state from Up to Down after receiving the last Hello+ packets. When a port is in an Up state, it expects to receive a Hello+ packet from its peer every “Hello Time” period to maintain its Up state. When it does not receive a Hello+ packet after an “Up Timeout” period, it changes its ELSM state from Up to Down. It is equal to [Hello Time * UpTimer Threshold].
RX Hello+—The number of Hello+ messages received by the port.
Rx Hello- —The number of Hello- messages received by the port.
Tx Hello+—The number of Hello+ messages sent by the port.
Tx Hello- —The number of Hello- messages sent by the port.
ELSM Up/Down Count—The number of times ELSM has been up or down.
To clear, reset the counters, use either the clear elsm {ports port_list} counters or the clear counters command.
You can also use the show ports {port_list} information {detail} command to display ELSM information.
L—Indicates that ELSM is enabled on the switch.
- —Indicates that ELSM is disabled on the switch.
up—Indicates that ELSM is enabled and the ELSM peer ports are up and communicating; the ELSM link state is up. In the up state, the ELSM-enabled port sends and receives hello messages from its peer.
dn—Indicates that ELSM is enabled, but the ELSM peers are not communicating; the ELSM link state is down. In the down state, ELSM transitions the peer port on this device to the down state. ELSM blocks all incoming and outgoing switching traffic and all control traffic except ELSM PDUs.
- —Indicates that ELSM is disabled on the switch.
If you specify the optional detail parameter, the following ELSM output is called out in written explanations versus displayed in a tabular format:
Up—Indicates that ELSM is enabled and the ELSM peer ports are up and communicating; the ELSM link state is up. In the up state, the ELSM-enabled port sends and receives hello messages from its peer.
Down—Indicates that ELSM is enabled, but the ELSM peers are not communicating; the ELSM link state is down. In the down state, ELSM transitions the peer port on this device to the down state. ELSM blocks all incoming and outgoing switching traffic and all control traffic except ELSM PDUs.
Enabled—Indicates that ELSM is enabled on the switch.
Disabled—Indicates that ELSM is disabled on the switch.
The following command displays detailed ELSM information for all configured ports on the switch:
show elsm ports all
The following is sample output from this command:
ELSM Info Port 4:4 Link State : Active ELSM Link State : Up ELSM State : Up Hello Transmit State : HelloRx(+) Hello Time : 100 msec Hold Threshold : 2 UpTimer Threshold : 6 Auto Restart : Enabled Down Timeout : 400 msec Up Timeout : 600 msec Rx Hello+ : 667960 Rx Hello- : 0 Tx Hello+ : 667958 Tx Hello- : 0 ELSM Up/Down Count : UP: 0 DOWN: 0 ELSM Info Port 4:4 Link State : Active ELSM Link State : Up ELSM State : Up Hello Transmit State : HelloRx(+) Hello Time : 100 msec Hold Threshold : 2 UpTimer Threshold : 6 Auto Restart : Disabled Sticky Threshold : 1 Sticky Threshold Counter : 0 Down Timeout : 400 msec Up Timeout : 600 msec Rx Hello+ : 708204 Rx Hello- : 0 Tx Hello+ : 708201 Tx Hello- : 0 ELSM Up/Down Count : UP: 0 DOWN: 0
This command was first available in ExtremeXOS 11.4.
This command is available on ExtremeSwitching 5320, 5420, 5520, and 5720 series switches.