Dell PowerConnect B-RX Configuration Manual page 221

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Configuring port flap dampening on an interface
This feature is configured at the interface level.
BigIron RX(config)# interface ethernet 2
BigIron RX(config-if-e100-2)# link-error-disable 10 3 10
Syntax: [no] link-error-disable <toggle-threshold> <sampling-time-in-sec> <wait-time-in-sec>
The <toggle-threshold> is the number of times a port's link state goes from up to down and down to
up before the wait period is activated. The default is 0. Enter a value from 1 – 50.
NOTE
Brocade does not advise setting the <toggle-threshold> to a value lower than 2 for the following
reason: When LACP is enabled on both the local and remote ends of a link, and port flap dampening
is enabled on the local link, when the remote system forms a trunk group dynamically, it will disable
then re-enable all member ports of that trunk group. The local system will detect and count this
transition as an up-to-down toggle.
The <sampling-time-in-sec> is the amount of time during which the specified toggle threshold can
occur before the wait period is activated. The default is 0 seconds. Enter a value between 1 and
65565 seconds.
The <wait-time-in-sec> is the amount of time the port remains disabled (down) before it becomes
enabled. Entering 0 indicates that the port will stay down until an administrative override occurs.
Enter a value between 0 and 65565 seconds.
Configuring port flap dampening on a trunk
You can configure the port flap dampening feature on the primary port of a trunk using the
link-error-disable command. Once configured on the primary port, the feature is enabled on all
ports that are members of the trunk. You cannot configure port flap dampening on port members
of the trunk.
Enter commands such as the following on the primary port of a trunk.
BigIron RX(config)# interface ethernet 2
BigIron RX(config-if-e100-2)#link-error-disable 10 3 10
Re-enabling a port disabled by port flap dampening
A port disabled by port flap dampening is automatically re-enabled once the wait period expires;
however, if the wait period is set to zero (0) seconds, you must re-enable the port by entering the
following command on the disabled port.
BigIron RX(config)# interface ethernet 2
BigIron RX(config-if-e100-2)# no link-error-disable 10 3 10
BigIron RX Series Configuration Guide
53-1002253-01
The sampling time or window (the time during which the specified toggle threshold can occur
before the wait period is activated) is triggered when the first "up to down" transition occurs.
"Up to down" transitions include UDLD-based toggles, as well as the physical link state.
Port transition hold timer
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