Deployment Guide

• If the interface states are shutdown, the sampling rate is set using the global sampling rate.
• If the global sample rate is non-default, for example 256 bytes, and if the sampling rate is not congured on an interface, the sampling
rate of the interface is the global non-default sampling rate, that is 256 bytes.
To avoid the back-o, either increase the global sampling rate or congure all the line card ports with the desired sampling rate even if
some ports have no sFlow congured.
Important Points to Remember
•
The Dell Networking OS implementation of the sFlow MIB supports sFlow conguration using the snmpset command.
• The Dell Networking OS exports all sFlow packets to the collector. A small sampling rate can equate to many exported packets. A
backo mechanism is automatically applied to reduce this amount. Some sampled packets may be dropped when the exported packet
rate is high and the backo mechanism is about to or is starting to take eect. The dropEvent counter, in the sFlow packet, is always
zero.
• Community list and local preference elds are not lled in extended gateway element in the sFlow datagram.
• 802.1P source priority eld is not lled in extended switch element in sFlow datagram.
• Only Destination and Destination Peer AS number are packed in the dst-as-path eld in extended gateway element.
• If the packet being sampled is redirected using policy-based routing (PBR), the sFlow datagram may contain incorrect extended
gateway/router information.
• The source virtual local area network (VLAN) eld in the extended switch element is not packed in case of routed packet.
• The destination VLAN eld in the extended switch element is not packed in a Multicast packet.
• On the switch, up to 700 packets can be sampled and processed per second.
Enabling and Disabling sFlow
By default, sFlow is disabled globally on the system.
Use the following command to enable sFlow globally.
• Enable sFlow globally.
CONFIGURATION mode
[no] sflow enable
Enabling and Disabling sFlow on an Interface
By default, sFlow is disabled on all interfaces.
This CLI is supported on physical ports and link aggregation group (LAG) ports.
To enable sFlow on a specic interface, use the following command.
• Enable sFlow on an interface.
INTERFACE mode
[no] sflow enable
To disable sFlow on an interface, use the no version of this command.
Enabling sFlow Max-Header Size Extended
To congure the maximum header size of a packet to 256 bytes, use the following commands:
• Set the maximum header size of a packet.
CONFIGURATION mode
sFlow
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