4.21 sFlow Configuration
The sFlow Configuration page allows for configuring sFlow. The configuration is divided into two parts: Configuration of the sFlow receiver (that is, sFlow collector) and configuration of per-port flow and counter samplers.
sFlow configuration is not persisted to non-volatile memory, which means that a reboot disables sFlow sampling.
The sFlow Configuration page has the following parameters:
- Agent Configuration
- IP Address: The IP address used as Agent IP address in sFlow datagrams. It serves as a unique key that identifies this agent over extended periods of time. Both IPv4 and IPv6 addresses are supported.
- Receiver Configuration
- Owner:
Basically, sFlow can be configured in two ways: Through local management
using the web or CLI interface, or through SNMP. This read-only field shows
the owner of the current sFlow configuration and assumes values as
follows:
- If sFlow is currently unconfigured/unclaimed, Owner contains <none>
- If sFlow is currently configured through web or CLI, Owner contains <Configured through local management>
- If sFlow is currently configured through SNMP, Owner contains a string identifying the sFlow receiver. If sFlow is configured through SNMP, all controls except for the Release button, are disabled to avoid inadvertent reconfiguration.
The RELEASE button allows for releasing the current owner and disable sFlow sampling. The button is disabled if sFlow is currently unclaimed. If configured through SNMP, the release must be confirmed (a confirmation request appears).
- IP Address/Hostname: The IP address or hostname of the sFlow receiver. Both IPv4 and IPv6 addresses are supported.
- UDP Port: The UDP port on which the sFlow receiver listens to sFlow datagrams. If set to 0 (zero), the default port (6343) is used.
- Timeout: The number of seconds remaining before sampling stops and the current sFlow owner is released. While active, the current time left can be updated by clicking on Refresh. If locally managed, the timeout can be changed on the fly without affecting any other settings. Valid range is 0 to 2147483647 seconds.
- Max. Datagram Size: The maximum number of data bytes that can be sent in a single sample datagram. This must be set to a value that avoids fragmentation of the sFlow datagrams. The valid range is 200 to 1468 bytes with default being 1400 bytes.
- Owner:
Basically, sFlow can be configured in two ways: Through local management
using the web or CLI interface, or through SNMP. This read-only field shows
the owner of the current sFlow configuration and assumes values as
follows:
- Port Configuration
- Port: The port number for which the configuration below applies
- Flow Sampler Enabled: Enables/disables flow sampling on this port
- Flow Sampler Sampling Rate: The statistical sampling rate for packet sampling. Set to N to sample on average 1/Nth of the packets transmitted/received on the port. Not all sampling rates are achievable. If an unsupported sampling rate is requested, the switch automatically adjusts it to the closest achievable. This is reported back in this field. The valid range is 1–4096.
- Flow Sampler Max.
Header: The maximum number of bytes that must be copied from
a sampled packet to the sFlow datagram. The valid range is 14–200 bytes with
default being 128 bytes.
To have room for any frame, the maximum datagram size must be roughly 100 bytes larger than the maximum header size. If the maximum datagram size does not consider the maximum header size, samples may be dropped.
- Counter Poller Enabled: Enables/disables counter polling on this port
- Counter Poller Interval: With counter polling enabled, this specifies the interval, in seconds, between counter poller samples. The valid range is 1s–3600s.