Storm Control for Broadcast, Unknown
Unicast, and Multicast Traffic
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.
- It can only be configured on physical interfaces in SLX 9540,
SLX 9640, SLX 9150, SLX 9250,
Extreme 8520, and Extreme 8720.
- For LAG ports, BUM RL needs to be attached to each LAG member port on
SLX 9150, SLX 9250, SLX 9540,
SLX 9640, Extreme 8520, and Extreme 8720.
- On SLX 9740/Extreme 8820,
BUM RL is applied directly on LAG. If there are multiple LAG
members on one line card, the CIR on that Line card is limited to configured
CIR. The CIR will not be applied per member port, but on the LAG. Hardware
creates and maintains policer on each core separately, hence there will be
Rate-limiting applied per core, and in case where Rate-limiting is done on Port
Channel and there are Port-Channel members across cores / Units, we will see
separate Rate-limiting applied. It is advisable to have the port Channel members
to be part of the same core, to have uniform Rate-limiting.
- 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.
- On SLX 9150, SLX 9250, Extreme 8520,
and Extreme 8720 only hit counters are supported, hence violated counters
will not be updated.
- In SLX 9540, SLX 9640, SLX 9740,
and Extreme 8820 only FWD and DROP
counters are supported.
-
-
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.
- In SLX 9540 and SLX 9640, FWD and DROP counters must
use a counter profile other than default.
- (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.