If you are installing the agent on Windows, then the installer will ask for the IP address of the sFlow collector as part of the installation. Just enter the IP address of your installation of sFlowTrend-Pro, and then when the installation is complete, host sFlow will be sent there.
When installing on Linux, a little more configuration is required. This can be done in two ways: either via DNS Service Discovery (DNS-SD) (see Section B.2.1, “Linux configuration using DNS Service Discovery”) or by editing a configuration file (Section B.2.2, “Linux configuration using the configuration file”). First, perform one of these configuration steps. Once complete, then start the service using the normal Linux service management command:
# service hsflowd start
If you are able to configure your local DNS servers, then the recommended way to configure host sFlow on Linux is via DNS Service Discovery. The sFlow configuration is placed into DNS records, which are then read by each sFlow host agent. This allows a large network of hosts to be easily configured and reconfigured as required.
The default configuration file is set for DNS-SD, so no changes are required there. Just add the following records to your DNS servers (used by the hosts to be monitored), and the hosts will then pick up the configuration automatically.
The following is an example configuration for DNS-SD. One
TXT
record should be created, with the name field
_sflow._udp
. This defines the overall sampling
parameters for the agent. Following this, add an
SRV
record to specify each collector
(eg instance of sFlowTrend-Pro) to send sFlow to.
_sflow._udp TXT "txtvers=1" "sampling=400" "polling=20" SRV 0 0 6343 sflowtrend.inmon.com SRV 0 0 6343 10.1.2.5.
This specifies a sample rate of 1 in 400, a counter polling
rate of every 20 seconds (recommended settings), and then
two sFlow destinations: one host called
sflowtrend.inmon.com
,
and another with the IP address of 10.1.2.5
,
both using the standard UDP 6343 sFlow port.
Note that the period after an IP address is often required.
For your configuration, replace the SRV
entries with those appropriate to your installation.
If you are unable to modify your DNS servers, or would prefer just to try out host sFlow by editing the configuration file on a few systems, then follow this example.
The configuration file is /etc/hsflowd.conf
.
Edit this file, and
first change the line DNSSD
to
DNSSD = off
This switches off DNS-SD; otherwise, the rest of the configuration
file is ignored. Then, uncomment the collector
section at the end of the file, and modify to suit your
installation. To have the same effect as the example in
Section B.2.1, “Linux configuration using DNS Service Discovery” use
this for the configuration file:
sflow { packetSamplingRate=400 counterPollingInterval=20 collector { ip=sflowtrend.inmon.com udpport=6343 } collector { ip = 10.1.2.5 udpport = 6343 } }