Dell PowerConnect B-FCXs, Configuration Manual

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PowerConnect B-Series FCX Configuration Guide 49
53-1002266-01
Configuring basic port parameters
2
If the port link state toggles from up to down for a specified number of times within a specified
period, the interface is physically disabled for the specified wait period. Once the wait period
expires, the port link state is re-enabled. However, if the wait period is set to zero (0) seconds, the
port link state will remain disabled until it is manually re-enabled.
Configuration notes
•
When a flap dampening port becomes a member of a trunk group, that port, as well as all
other member ports of that trunk group, will inherit the primary port configuration. This means
that the member ports will inherit the primary port flap dampening configuration, regardless of
any previous configuration.
•
The Dell PowerConnect device counts the number of times a port link state toggles from "up to
down", and not from "down to up".
•
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.
Configuring port flap dampening on an interface
This feature is configured at the interface level.
PowerConnect(config)# interface ethernet 2/1
PowerConnect(config-if-e10000-2/1)# 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 link state goes from up to down and down to
up before the wait period is activated. Enter a value from 1 - 50.
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 1 – 65535 seconds.
The <wait-time-in-sec> is the amount of time the port remains disabled (down) before it becomes
enabled. Enter a value from 0 – 65535 seconds; 0 indicates that the port will stay down until an
administrative override occurs.
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.
PowerConnect(config)# interface ethernet 2/1
PowerConnect(config-if-e10000-2/1)# 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.