Enterasys Matrix DFE-Gold Series Configuration Manual page 574

Configuring NetFlow
Parameters
refresh‐rate packets
timeout minutes
Defaults
At least one of the refresh‐rate or timeout parameters must be specified, although both can be
specified on one command line.
Mode
Switch command, Read‐Write.
Usage
Version 9 template records have a limited lifetime and must be periodically refreshed. Templates
are retransmitted when either:
• The packet refresh rate is reached, or
• The template timeout is reached.
Template refresh based on the timeout period is performed on every blade. Since each DFE blade
handles its own packet transmissions, template refresh based on number of export packets sent is
managed by each blade independently.
The refresh rate defines the maximum delay a new or restarted NetFlow collector would
experience until it learns the format of the data records being forwarded (from the template
referenced by the data records). Refresh rates affect NetFlow collectors during their start up when
they must ignore incoming data flow reports until the required template is received.
Setting the appropriate refresh rate for your Enterasys Matrix system must be determined, since
the default settings of a 20 packet refresh rate and a 30 minute timeout may not be optimal for
your environment. For example, a switch processing an extremely slow flow rate of, say, 20
packets per half hour, would refresh the templates only every half hour using the default settings,
while a switch sending 300 flow report packets per second would refresh the templates 15 times
per second.
Enterasys recommends that you configure your Enterasys Matrix system so it does not refresh
templates more often than once per second.
Use the show netflow config command ("show netflow" on page 15‐3) to display the currently
configured values.
Example
This example shows how to set the Version 9 template packet refresh rate to 50 packets and the
timeout value to 45 minutes:
Matrix(rw)->set netflow template refresh-rate 50 timeout 45
15-10 NetFlow Configuration
The number of export packets sent that causes a template to be
retransmitted by an individual DFE blade.
The value of packets can range from 1 to 600. The default value is 20
packets.
The length of the timeout period, in minutes, after which a template is
retransmitted by all blades in the system.
The value of minutes can range from 1 to 3600. The default value is 30
minutes.
set netflow template