Dell PowerConnect B-RX - Chapter 39 Configuring Sflow; Configuration Considerations

BigIron RX Series Configuration Guide 1039
53-1002253-01
Chapter
39
Configuring sFlow
The sFlow feature is a system for observing traffic flow patterns and quantities within and among a
set of BigIron RX devices. Participating devices also relay byte and packet counter data (counter
samples) for ports to the collector.
sFlow is described in RFC 3176, “InMon Corporation's sFlow, A Method for Monitoring Traffic in
Switched and Routed Networks”. Refer to this RFC to determine the contents of the sampled
packet.
Configuration considerations
Consider the following when you configure sFlow:
• Sample data is collected from inbound traffic on ports enabled for sFlow. However, both traffic
directions are counted for byte and packet counter statistics sent to the collector.
• sFlow packets are not forwarded on the management interface, you will need to configure the
IP interface on a line module to forward the sFlow packets.
• sFlow can not be configured on Link Aggregation ports until Link Aggregation is established.
Once Link Aggregation is established, then the sFlow parameter appears on the interface
mode which is configured Link Aggregation.
Source address
The sampled sFlow data sent to the collectors includes an agent_address field. This field identifies
the IP address of the device that sent the data.
sFlow looks for an IP address in following order, and uses the first address found:
• The router ID configured by the ip router-id command
• The first IP address on the lowest-numbered loopback interface
• The first IP address on the lowest-numbered virtual interface
• The first IP address on any interface
NOTE
The device uses the router ID only if the device also has an IP interface with the same address.
NOTE
If an IP address is not already configured when you enable sFlow, the feature uses the source
address 0.0.0.0. To display the agent_address, enable sFlow, then enter the show sflow command.
Refer to “Enabling sFlow forwarding” on page 1043 and “Displaying sFlow information” on
page 1047.
NOTE
If you change the address sFlow will use for the agent_address, you must disable and re-enable
sFlow to enable the feature to use the changed address.