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Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x
Chapter 2 Configuring Interfaces
Information About Interfaces
Port Monitor Port Guard
Port monitor port guard is a feature that disables or shuts down a port when an event occurs. Depending
on the configuration, when an event occurs the port is either error-disabled or flapped.
Port monitor port guard is a different or separate feature that functions based on the configuration of the
errordisable command.
Port Group Monitor
Each line card or module has a predefined set of ports which share the same backplane bandwidth called
port groups. While oversubscription is a feature, the port group monitor feature helps to monitor the
spine bandwidth utilization. An alarm syslog is generated so that you can provision the ports across port
groups evenly to manage the oversubscription better.
When the port group monitor feature is enabled and a policy consisting of polling interval in seconds,
and the raising and falling thresholds in percentage are specified, port group monitor generates a syslog
if a port group traffic goes above the specified percentage of the maximum supported bandwidth for that
port group (for rx and for tx) and another syslog if the value falls below the specified threshold.
The default port group policy has the following threshold values:
Local Switching
Local switching can be enabled in Generation 4 modules, which allows traffic to be switched directly
with a local crossbar when the traffic is directed from one port to another on the same line card. By using
local switching, an extra switching step is avoided, which decreases the latency.
When using local switching, note the following guidelines:
• All ports need to be in shared mode, which usually is the default state. To place a port in shared
mode, enter the switchport ratemode shared command.
• E ports are not allowed in the module because they must be in dedicated mode.
Note Local Switching is not supported on MDS 9710.
RX Performance Delta 60 2147483648 4 524288000 4
TX Performance Delta 60 2147483648 4 524288000 4
Counter
Threshold
Type
Interval
(Seconds)
% Rising
Threshold Event
% Falling
Threshold Event
Counter Threshold Type Interval (Seconds) % Rising Threshold % Falling Threshold
RX Performance Delta 60 80 20
TX Performance Delta 60 80 20
