Storm Control - Dell C9000 Series Reference Manual

The Dell Networking operating software storm control feature allows you to limit or suppress traffic during a
traffic 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 configuration on ingress.
• An INTERFACE-level command overrides any CONFIGURATION-level ingress command for that
physical interface, if both are configured.
• 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 configured for the data traffic, the traffic 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 configured for the data traffic, the traffic goes to queue 2 instead of queue 0.
NOTE: Bi-directional traffic (unknown unicast and broadcast) along with egress storm control causes the
configured traffic rates split between the involved ports. The percentage of traffic that each port receives
after the split is not predictable. These ports can be in the same/different port pipes or the same/different
line cards.
NOTE: The policy discard drop counters are common across storm-control drops, ACL drops and QoS
drops. Therefore, if your configuration includes ACL and QoS, those drops are also computed and
displayed in the policy discard drops counter field 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 field of
the output of the show hardware stack-unit stack—unit—number drops command.
Topics:
• show storm-control broadcast
• show storm-control multicast
• show storm-control unknown-unicast
• storm-control broadcast (Configuration)

Storm Control

Storm Control
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