Extreme Networks ExtremeWare 7.7, Command Reference Manual

Page: 1505 / 2620

configure elsm hellotime
ExtremeWare 7.7 Command Reference Guide 1505
configure elsm hellotime
configure elsm hellotime <1-128> ports <portlist>
Description
Configures the Extreme Link Status Monitoring (ELSM) hello timer by specifying the time between
consecutive ELSM hellos for the specified ports.
Syntax Description
Default
1.
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:
disable 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>
hellotime <1-128> Specifies the time, in seconds between consecutive hellos. Use the same
value for the hello interval on peer ports. The default is 1. The range is 1 to
128.
portlist Specifies the ports or slots and ports for which the ELSM hello timer should
be configured. May be in the form 1, 2, 3-5, 2:5, 2:6-2:8.