Reference Guide

sFlow
sFlow is a standard-based sampling technology embedded within switches and routers which is used to monitor network trac. It is
designed to provide trac monitoring for high-speed networks with many switches and routers.
• OS10 supports sFlow version 5
• sFlow collector is supported only on data ports
• Maximum of two sFlow collectors
• Does not support sFlow on SNMP, VLAN, VRF, and tunnel interfaces
• Does not support extended sFlow, backo mechanism, and egress sampling in sFlow
sFlow uses two types of sampling:
• Statistical packet-based sampling of switched or routed packet ows
• Time-based sampling of interface counters
The sFlow monitoring system consists of an sFlow agent (embedded in the device) and an sFlow collector. The sFlow agent resides
anywhere within the path of the packet and combines the ow samples and interface counters into sFlow datagrams and forwards them to
the sFlow collector at regular intervals. The datagrams consist of information on, but not limited to, packet header, ingress and egress
interfaces, sampling parameters, and interface counters. Application-specic integrated circuits (ASICs) handle the packet sampling.
The sFlow collector analyses the datagrams received from dierent devices and produces a network-wide view of trac ows.
Enable sFlow
You can enable sFlow either on all interfaces globally or on a specic set of interfaces. The system displays an error message if you try to
enable sFlow on both the modes at a time.
If you congure sFlow only on a set of interfaces, any further change to the sFlow-enabled ports triggers the sFlow agent to restart. This
results in a gap in the polling counter statistics of 30 seconds and the sFlow counters are reset on all the sFlow-enabled ports.
When you enable sFlow on a port-channel:
• When you enable sFlow in per-interface mode, the counter statistics of sFlow-enabled ports are reset to zero when a new member port
is added or an existing member port is removed from any sow enabled port-channel group.
• sFlow counter statistics that are individually reported for the port members of a port-channel data source are accurate. Counter
statistics reported for the port-channel may not be accurate. To calculate the correct counters for a port-channel data source, add
together the counter statistics of the individual port members.
Enable sFlow globally
sFlow is disabled globally by default.
• Enable sFlow globally on all interfaces in CONFIGURATION mode.
sflow enable all-interfaces
• Disable sFlow in CONFIGURATION mode.
no sflow
10
546 sFlow