Brocade Communications Systems 6650 Changing the polling interval, Changing the sampling rate

sFlow 11

Specifying an sFlow collector on IPv6 devices

To specify an sFlow collector on an IPv6 device, enter a command such as the following.

Brocade(config)#sflow destination ipv6 2001:DB8:0::0b:02a

This command specifies a collector with IPv6 address 2001:DB8:0::0b:02a, listening for sFlow data on UDP port 6343.

Syntax: [no] sflow destination ipv6 <ip-addr>[<dest-udp-port>]

The <ip-addr>parameter specifies the IP address of the collector.

The <dest-udp-port>parameter specifies the UDP port on which the sFlow collector will be listening for exported sFlow data. The default port number is 6343.

If the IPv6 address you specify is a link-local address on a Layer 3 switch, you must also specify the outgoing-interface ethernet <stack-unit>/<slot>/<port>or the ve <port-num>. This identifies the outgoing interface through which the sampled packets will be sent.

The sampled sFlow data sent to the collectors includes an agent_address field. This field identifies the device that sent the data. Refer to “sFlow and source address” on page 256.

Changing the polling interval

The polling interval defines how often sFlow byte and packet counter data for a port are sent to the sFlow collectors. If multiple ports are enabled for sFlow, the Brocade ICX 6650 device staggers transmission of the counter data to smooth performance. For example, if sFlow is enabled on two ports and the polling interval is 20 seconds, the Brocade ICX 6650 device sends counter data every ten seconds. The counter data for one of the ports are sent after ten seconds, and counter data for the other port are sent after an additional ten seconds. Ten seconds later, new counter data for the first port are sent. Similarly, if sFlow is enabled on five ports and the polling interval is 20 seconds, the Brocade device sends counter data every four seconds.

The default polling interval is 20 seconds. You can change the interval to a value from 1 to any higher value. The interval value applies to all interfaces on which sFlow is enabled. If you set the polling interval to 0, counter data sampling is disabled.

To change the polling interval, enter a command such as the following at the global CONFIG level of the CLI.

Brocade(config)#sflow polling-interval 30

Syntax: [no] sflow polling-interval <secs>

The <secs> parameter specifies the interval and can be from 1 to any higher value. The default is 20 seconds. If you specify 0, counter data sampling is disabled.

Changing the sampling rate

The sampling rate is the average ratio of the number of packets incoming on an sFlow-enabled port, to the number of flow samples taken from those packets.

You can change the default (global) sampling rate. You also can change the rate on an individual port, overriding the default sampling rate of 512. With a sampling rate of 512, on average, one in every 512 packets forwarded on an interface is sampled.

Brocade ICX 6650 Administration Guide	259
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