Reference Guide

824 | sFlow
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The polling interval can be configured globally (in CONFIGURATION mode) or by interface (in
INTERFACE mode) by executing the interval command:
.
Back-off Mechanism
If the sampling rate for an interface is set to a very low value, the CPU can get overloaded with flow
samples under high-traffic conditions. In such a scenario, a binary back-off mechanism gets triggered,
which doubles the sampling-rate (halves the number of samples per second) for all interfaces. The backoff
mechanism continues to double the sampling-rate until CPU condition is cleared. This is as per sFlow
version 5 draft. Once the back-off changes the sample-rate, users must manually change the sampling rate
to the desired value.
As a result of back-off, the actual sampling-rate of an interface may differ from its configured sampling
rate. The actual sampling-rate of the interface and the configured sample-rate can be viewed by using the
show sflow command.
sFlow on LAG ports
When a physical port becomes a member of a LAG, it inherits the sFlow configuration from the LAG port.
Command Syntax Command Mode Usage
sflow polling-interval
interval value
CONFIGURATION or
INTERFACE
Change the global default counter polling interval.
interval value—in seconds.
Range: 15 to 86400 seconds
Default: 20 seconds