Service Manual

55
Storm Control
The Dell Networking operating software storm control feature allows you to limit or suppress trac during a trac storm
(Broadcast/Unknown Unicast Rate Limiting or Multicast on the C-Series and S-Series).
Storm control is supported on Dell Networking OS.
Important Points to Remember
• Interface commands can only be applied on physical interfaces (virtual local area networks [VLANs] and link aggregation group
[LAG] interfaces are not supported).
• An INTERFACE-level command only supports storm control conguration on ingress.
• An INTERFACE-level command overrides any CONFIGURATION-level ingress command for that physical interface, if both are
congured.
• You can apply the CONFIGURATION-level storm control commands at ingress or egress and are supported on all physical
interfaces.
• When storm control is applied on an interface, the percentage of storm control applied is calculated based on the advertised rate
of the line card. It is not based on the speed setting for the line card.
• Do not apply per-VLAN quality of service (QoS) on an interface that has storm control enabled (either on an interface or
globally).
• When you enable broadcast storm control on an interface or globally on ingress, and DSCP marking for a DSCP value 1 is
congured for the data trac, the trac goes to queue 1 instead of queue 0.
• Similarly, if you enable unicast storm control on an interface or globally on ingress, and DSCP marking for a DSCP value 2 is
congured for the data trac, the trac goes to queue 2 instead of queue 0.
NOTE: Bi-directional trac (unknown unicast and broadcast) along with egress storm control causes the congured
trac rates split between the involved ports. The percentage of trac that each port receives after the split is not
predictable. These ports can be in the same/dierent port pipes or the same/dierent line cards.
NOTE: The policy discard drop counters are common across storm-control drops, ACL drops and QoS drops. Therefore, if
your conguration includes ACL and QoS, those drops are also computed and displayed in the policy discard drops
counter eld along with storm-control drops. The packets dropped by the storm control feature can be monitored by
viewing the value of the Policy Discard Drops eld of the output of the show hardware stack-unit stack—unit—
number drops command.
show storm-control broadcast
Display the storm control broadcast conguration.
Syntax
show storm-control broadcast [interface]
Parameters
interface (OPTIONAL) Enter one of the following interfaces to display the interface-specic
storm control conguration:
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Storm Control