Concept Guide

• Congure storm control.
INTERFACE mode
• Congure the packets per second of broadcast trac allowed on an interface (ingress only).
INTERFACE mode
storm-control broadcast packets_per_second in
• Congure the packets per second of multicast trac 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 congured 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.
Conguring Storm Control from CONFIGURATION Mode
To congure storm control from CONFIGURATION mode, use the following command.
From CONFIGURATION mode you can congure storm control for ingress and egress trac.
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).
• Congure storm control.
CONFIGURATION mode
• Congure the packets per second of broadcast trac allowed in the network.
CONFIGURATION mode
storm-control broadcast packets_per_second in
• Congure the packets per second (pps) of multicast trac allowed on C-Series and S-Series networks only.
CONFIGURATION mode
storm-control multicast packets_per_second in
• Congure the packets per second of unknown-unicast trac allowed in or out of the network.
CONFIGURATION mode
storm-control unknown-unicast packets_per_second in
PFC Storm
When packets ood a network, the result is excessive trac which aects the performance of the network. When Priority Flow Control
(PFC) is enabled on a port, the trac ows according to the priority of the data.
PFC storm is the inconsistencies found in the trac that ows 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 trac with the corresponding egress counter not getting
incremented, then the condition is detected as PFC storm. During such conditions, the trac corresponding to the port or priority can be
dropped for a specic 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
trac corresponding to other priorities is not aected. You can restore the dropped queue to normal state after a period of time.
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Storm Control