Supermicro SuperBlade SBM-GEM-X2C, User Manual

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Chapter 6: 1-Gb Ethernet Switch Firmware
6-8 Rate Control
The switch supports per-port rate control. When the data rate of the incoming frame for
a particular port exceeds a selected rate, the excess frame traffic is subject to packet
drops or flow control, depending on the per-port flow control configuration in the P
ORT
folder. If the flow control of a particular port is enabled, then the switch uses flow control
to inhibit any excess traffic. If the flow control is disabled, the excess frames will be
dropped.
To configure the ingress rate limit for a port, click on R
ATE
in the left-hand side bar. The
R
ATE
L
IMIT AND
S
TORM
C
ONTROL
screen appears as Figure 6-14 .
The screen shows the Ingress Rate (in kilobits per sec) for all ports. Click on the port
number to control the ingress rates for the port. There are eight different levels to select:
no limit (1Gbps) , 256Kbps , 1Mbps , 4Mbps , 16Mbps , 64Mbps , 128Mbps or 512Mbps .
The S
TORM
C
ONTROL
indicates the current status of storm control.
A traffic storm happens when broadcast, multicast or unknown unicast packets flood the
network, which will degrade the network performance. The storm control monitors the
traffic of an incoming particular type of frame (configured by the user) and limits traffic to
a user configurable rate level (threshold). The storm rate threshold is counted in number
of packets per second (pps). If the traffic of a particular frame type exceeds the
threshold during one second, all the rest of that type of frame will be dropped before the
end of that second.
The switch provides configuration to assign storm control type and rate limitations to the
entire system.
Figure 6-14. Rate Limit and Storm Control Screen