Brocade FastIron Ethernet Switch Administration Guide - Manual (Page 244)

sFlow
NOTE
FastIron devices support sFlow version 5 by default.
sFlow is a standards-based protocol that allows network traffic to be sampled at a user-defined rate for
the purpose of monitoring traffic flow patterns and identifying packet transfer rates on user-specified
interfaces.
When sFlow is enabled on a Layer 2 or Layer 3 switch, the system performs the following sFlow-
related tasks:
• Samples traffic flows by copying packet header information
• Identifies ingress and egress interfaces for the sampled flows
• Combines sFlow samples into UDP packets and forwards them to the sFlow collectors for analysis
• Forwards byte and packet count data, or counter samples, to sFlow collectors
sFlow is described in RFC 3176, "InMon Corporation's sFlow: A Method for Monitoring Traffic in
Switched and Routed Networks".
On ICX and FCX Series devices, you can use QoS queue 1 for priority traffic, even when sFlow is
enabled on the port. This differs from FastIron X Series devices, which support seven priorities instead
of eight when sFlow is enabled. In this case, QoS queue 1 is reserved for sFlow and is not used by
other packets. Any non-sFlow packets assigned to QoS queue 1 will be directed to QoS queue 0.
sFlow version 5
sFlow version 5 enhances and modifies the format of the data sent to the sFlow collector. sFlow
version 5 introduces several new sFlow features and also defines a new datagram syntax used by the
sFlow agent to report flow samples and interface counters to the sFlow collector.
sFlow version 5 adds support for the following:
• sFlow version 5 datagrams
• Sub-agent support
• Configurable sFlow export packet size
• Support for the new data field and sample type length in flow samples
• Configurable interval for exporting Brocade-specific data structure
sFlow version 5 is backward-compatible with sFlow version 2. By default, the sFlow agent exports
sFlow version 5 flow samples by default, but you can configure the device to export the data in sFlow
version 2 format. You can switch between sFlow version 2 and sFlow version 5 formats. The sFlow
collector automatically parses each incoming sample and decodes it based on the version number.
The configuration procedures for sFlow version 5 are the same as for sFlow version 2, except where
explicitly noted. Configuration procedures for sFlow are in the section
Configuring and enabling sFlow
on page 247. The features and CLI commands that are specific to sFlow version 5 are described in
the section
sFlow version 5 feature configuration on page 253.
sFlow support for IPv6 packets
The Brocade implementation of sFlow features support IPv6 packets. This support includes extended
router information and extended gateway information in the sampled packet. Note that sFlow support
for IPv6 packets exists only on devices running software that supports IPv6.
sFlow
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