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Brocade FastIron Ethernet Switch Administration Guide User Manual

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For example, if the configured sampling rate is 1000, then the actual rate is 2048 and 1 in 2048 packets
are sampled by the hardware.

Changing the sampling rate of a module

You cannot change a module sampling rate directly. You can change a module sampling rate only by
changing the sampling rate of a port on that module.

Changing the sampling rate on a port

You can configure an individual port to use a different sampling rate than the global default sampling
rate. This is useful in cases where ports have different bandwidths. For example, if you are using sFlow
on 10/100 ports and Gbps Ethernet ports, you might want to configure the Gbps ports to use a higher
sampling rate (and thus gather fewer samples per number of packets) than the 10/100 ports.

To change the sampling rate on an individual port, enter a command such as the following at the
configuration level for the port.

device(config-if-1/1)#sflow sample 8192

Syntax: [no] sflow samplenum

The num parameter specifies the average number of packets from which each sample will be taken.
The software rounds the value you enter up to the next odd power of 2. The actual sampling rate
becomes one of the values listed in the section

Changing the sampling rate

.

NOTE
Configuring a sampling rate on a port that is the primary port of a trunk applies that same sampling rate
to all ports in the trunk.

Changing the sampling rate for a trunk port

You can configure an individual static trunk port to use a different sampling rate than the global default
sampling rate. This feature is also supported on LACP trunk ports. This feature is useful in cases where
ports have different bandwidths. For example, if you are using sFlow on 10/100 ports and Gbps
Ethernet ports, you might want to configure the Gbps ports to use a higher sampling rate (and thus
gather fewer samples per number of packets) than the 10/100 ports.

To configure a static trunk port to use a different sampling rate than the global default sampling rate,
enter commands such as the following:

device(config)#trunk e 4/1 to 4/8

device(config-trunk-4/1-4/8)sflow sample 8192

Syntax: [no] sflow samplenum

The num parameter specifies the average number of packets from which each sample will be taken.
The software rounds the value you enter up to the next odd power of 2. The actual sampling rate
becomes one of the values listed in the section

Changing the sampling rate

.

Network Monitoring

FastIron Ethernet Switch Administration Guide

251

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