Users Guide

● Configure the packets per second of multicast traffic allowed on C-Series or S-Series interface (ingress only) network only.
INTERFACE mode
storm-control multicast packets_per_second in
● Shut down the port if it receives the PFC/LLFC packets more than the configured rate.
INTERFACE mode
storm-control pfc-llfc pps in shutdown
NOTE: PFC/LLFC storm control enabled interface disables the interfaces if it receives continuous PFC/LLFC packets.
It can be a result of a faulty NIC/Switch that sends spurious PFC/LLFC packets.
NOTE: After applying the storm-control configuration, traffic drop is expected if ingress traffic follows a burst pattern.
For example, storm-control broadcast 1000 in. This configuration allows the switch to forward only 1 packet
per millisecond. If a higher number of packets ingress at the switch interface within a duration of 1 millisecond, the
switch forwards the first packet and drops the remaining packets.
Configuring Storm Control from CONFIGURATION Mode
To configure storm control from CONFIGURATION mode, use the following command.
From CONFIGURATION mode you can configure storm control for ingress and egress traffic.
Do not apply per-virtual local area network (VLAN) quality of service (QoS) on an interface that has storm-control enabled
(either on an interface or globally).
● Configure storm control.
CONFIGURATION mode
● Configure the packets per second of broadcast traffic allowed in the network.
CONFIGURATION mode
storm-control broadcast packets_per_second in
● Configure the packets per second (pps) of multicast traffic allowed on C-Series and S-Series networks only.
CONFIGURATION mode
storm-control multicast packets_per_second in
● Configure the packets per second of unknown-unicast traffic allowed in or out of the network.
CONFIGURATION mode
storm-control unknown-unicast packets_per_second in
PFC Storm
When packets flood a network, the result is excessive traffic which affects the performance of the network. When Priority Flow
Control (PFC) is enabled on a port, the traffic flows according to the priority of the data.
Limitation: Dell EMC Networking OS does not support storm-control pfc, when the policy map uses trust diffserv for
packet classification.
PFC storm is the inconsistencies found in the traffic that flows through a PFC enabled port. You can detect this by polling the
lossless queues on each port. This polling is done at periodic intervals. If the queue has traffic with the corresponding egress
counter not getting incremented, then the condition is detected as PFC storm. During such conditions, the traffic corresponding
to the port or priority can be dropped for a specific period of time to overcome the degrade in the network performance.
Once you detect PFC storm on a port or priority, you can discard all packets on that port/priority and enable drop of the queue,
so that traffic corresponding to other priorities is not affected. You can restore the dropped queue to normal state after a
period of time.
Storm Control
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