Dell Brocade DCX, Configuration Manual

Page: 211 / 1436

BigIron RX Series Configuration Guide 139
53-1001810-01
Port transition hold timer
6
If the port flap state toggles (from down to up or 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’s link state is re-enabled. However, if the wait period is set to zero (0)
seconds, the port’s link state will remain disabled until it is manually re-enabled.
Configuration notes
•
When a link 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’s configuration. This means
that the member ports will inherit the primary port’s link dampening configuration, regardless
of any previous configuration.
•
The Brocade device counts the number of times a port’s 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.
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.