Enabling Extended Sflow - Dell S4048–ON Configuration Manual

• By default, sFlow collection is supported only on data ports. If you want to enable sFlow collection through management ports,
use the management egress-interface-selection and application sflow-collector commands in
Configuration and EIS modes respectively.
• Dell Networking OS exports all sFlow packets to the collector. A small sampling rate can equate to many exported packets. A
backoff mechanism is automatically applied to reduce this amount. Some sampled packets may be dropped when the exported
packet rate is high and the backoff mechanism is about to or is starting to take effect. The dropEvent counter, in the sFlow
packet, is always zero.
• Community list and local preference fields are not filled in extended gateway element in the sFlow datagram.
• 802.1P source priority field is not filled in extended switch element in sFlow datagram.
• Only Destination and Destination Peer AS number are packed in the dst-as-path field 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) field in the extended switch element is not packed in case of routed packet.
• The destination VLAN field in the extended switch element is not packed in a Multicast packet.
• Up to 700 packets can be sampled and processed per second.

Enabling Extended sFlow

Extended sFlow packs additional information in the sFlow datagram depending on the type of sampled packet. The S-Series and
Z9100–ON platforms support extended-switch information processing only.
Extended sFlow packs additional information in the sFlow datagram depending on the type of sampled packet. You can enable the
following options:
• extended-switch — 802.1Q VLAN ID and 802.1p priority information.
• extended-router — Next-hop and source and destination mask length.
• extended-gateway — Source and destination AS number and the BGP next-hop.
NOTE: The entire AS path is not included. BGP community-list and local preference information are not included. These
fields are assigned default values and are not interpreted by the collector.
• Enable extended sFlow.
sflow [extended-switch] [extended-router] [extended-gateway] enable
By default packing of any of the extended information in the datagram is disabled.
• Confirm that extended information packing is enabled.
show sflow
Examples of Verifying Extended sFlow
The bold line shows that extended sFlow settings are enabled on all three types.
Dell#show sflow
sFlow services are enabled
Egress Management Interface sFlow services are disabled
Global default sampling rate: 32768
Global default counter polling interval: 20
Global default extended maximum header size: 128 bytes
Global extended information enabled: none
1 collectors configured
Collector IP addr: 100.1.1.1, Agent IP addr: 1.1.1.2, UDP port: 6343 VRF: Default
0 UDP packets exported
0 UDP packets dropped
0 sFlow samples collected
stack-unit 1 Port set 0
Te 1/1: configured rate 16384, actual rate 16384
Dell#
If you did not enable any extended information, the show output displays the following (shown in bold).
Dell#show sflow
sFlow services are disabled
789
sFlow