•
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.
Enabling Extended sFlow
The S-Series 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 0 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
Global default sampling rate: 32768
Global default counter polling interval: 20
Global extended information enabled: none
0 collectors configured
0 UDP packets exported
0 UDP packets dropped
0 sFlow samples collected
0 sFlow samples dropped due to sub-sampling
681
sFlow