Configure Elsm Hold-Threshold - Extreme Networks ExtremeWare Command Reference Manual

ESRP Commands

configure elsm hold-threshold

configure elsm hold-threshold <1-3> ports <portlist>
Description
Configures the Extreme Link Status Monitoring (ELSM) hold threshold by specifying the number of
packets to transition out of the Down-Wait receive state to the Up receive state for the specified ports.
Syntax Description
hold-threshold <1-3>
portlist
Default
2.
Usage Guidelines
The Extreme Link Status Monitoring (ELSM) protocol allows you to detect remote CPU failures in the
network. A software or hardware fault might prevent the CPU from transmitting or receiving, leading
to the sudden failure of the CPU. If the CPU cannot process or send packets, ELSM isolates the
connections to the faulty switch from the rest of the network. If the switch fabric continues to send
packets during a CPU failure, the switch may appear to be healthy when it is not.
An Extreme Networks device with ELSM enabled can detect remote CPU failures by exchanging hello
packets between two ELSM peers. When ELSM detects a CPU failure as a result of not hearing from its
neighbor, it brings down the connection to the neighbor. ELSM operates on a point-to-point basis; you
only configure ELSM on the ports that connect to other devices within the network, but you must
configure ELSM on both sides of the peer connections.
ELSM ports use hello packets to communicate information about the health of the network to peer
ports. The hello packets are received and transmitted by an ELSM-enabled port. The port expects a
response from its neighbor after it sends a hello packet.
When you enable ELSM on the specified ports, the ports participate in ELSM with their peers and begin
exchanging ELSM hellos. Use the following command to enable ELSM:
enable elsm ports <portlist>
ELSM works between two connected ports, and each ELSM instance is based on a single port.
When you disable ELSM on the specified ports, the ports no longer send ELSM hellos to its peer and no
longer maintain ELSM states.
When you disable ELSM on the specified ports, the ports no longer send ELSM hellos to its peer and no
longer maintain ELSM states. Use the following command to disable ELSM:
disable elsm ports <portlist>
1058
Specifies the number of packets required to transition out of the Down-Wait
state to the Up state. A threshold of 1 means the ELSM port must receive at
least one Hello+ packet to transition from the Down-Wait state to the Up state.
The default is 2. The range is 1 to 3.
Specifies the ports or slots and ports for which the ELSM hold threshold
should be configured. May be in the form 1, 2, 3-5, 2:5, 2:6-2:8.
ExtremeWare Software 7.3.0 Command Reference Guide