Administrator Guide
Example of Viewing sFlow Conguration (Line Card)
Dell#show sflow Stack-unit 1
Stack-unit 1
Samples rcvd from h/w :0
Total UDP packets exported :0
UDP packets exported via RPM :0
UDP packets dropped :36
Conguring Specify Collectors
The sflow collector command allows identication of sFlow collectors to which sFlow datagrams are forwarded.
You can specify up to two sFlow collectors. If you specify two collectors, the samples are sent to both.
• Identify sFlow collectors to which sFlow datagrams are forwarded.
CONFIGURATION mode
sflow collector ip-address agent-addr ip-address [number [max-datagram-size number] ] | [max-
datagram-size number ]
The default UDP port is 6343.
The default max-datagram-size is 1400.
Changing the Polling Intervals
The sflow polling-interval command congures the polling interval for an interface in the maximum number of seconds between
successive samples of counters sent to the collector.
This command changes the global default counter polling (20 seconds) interval. You can congure an interface to use a dierent polling
interval.
To congure the polling intervals globally (in CONFIGURATION mode) or by interface (in INTERFACE mode), use the following command.
• Change the global default counter polling interval.
CONFIGURATION mode or INTERFACE mode
sflow polling-interval interval value
• interval value: in seconds.
The range is from 15 to 86400 seconds.
The default is 20 seconds.
Back-O Mechanism
If the sampling rate for an interface is set to a very low value, the CPU can get overloaded with ow samples under high-trac conditions.
In such a scenario, a binary back-o mechanism gets triggered, which doubles the sampling-rate (halves the number of samples per
second) for all interfaces. The backo mechanism continues to double the sampling-rate until the CPU condition is cleared. This is as per
sFlow version 5 draft. After the back-o changes the sample-rate, you must manually change the sampling rate to the desired value.
As a result of back-o, the actual sampling-rate of an interface may dier from its congured sampling rate. You can view the actual
sampling-rate of the interface and the congured sample-rate by using the show sflow command.
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sFlow