Storm Control for Broadcast, Unknown Unicast, and Multicast Traffic

A broadcast, unknown unicast, and multicast (BUM) traffic storm occurs when packets flood the LAN, creating excessive traffic and degrading network performance.

Use BUM storm control to limit the amount of BUM ingress traffic globally or on a specified physical interface. All ingress traffic in excess of the configured rate is discarded.

Consider the following when you configure storm control:

BUM storm control applies only to ingress traffic.
The device supports both global and interface-level BUM storm control.
BUM storm control and input service-policy features can coexist on an interface. BUM storm control has the higher precedence.
For LAG ports, enable BUM rate limiting on each LAG member port.
A Single-rate Two Color Marking (SrTCM) scheme is used.
Metering is performed on the packet size as received on the wire, including IPG (inter-packet gap) and preamble, but ignoring CRC (cyclic redundancy check).
BUM rate limiting is ineffective if the BUM traffic is also classified by an ACL.
The configured rate in bits per second (bps) is rounded up to next achievable rate.
Only FWD and DROP counters are supported. FWD and DROP counters must use a counter profile other than default.
- Conformed: Shows FWD packets including green and yellow color packets.
- ( SLX 9640 and SLX 9540 only) Violated: Shows DROP packets including red color packets.
- ( SLX 9640 and SLX 9540 only) Exceed: Is always ZERO.
( SLX 9640 and SLX 9540 only) When storm control is configured at the interface level, you can specify whether to shut down an interface if the maximum defined rate is exceeded within a 10-second sampling period. When a port is shut down, you receive a log message. From global configuration mode, shutdown is not supported.