12.04.2020

Tera flow

Tera Flow is FastNetMon’s own format for very high efficient flow representation which includes many improvements over existing flow protocols with main target to improve development experience and cross language support. FastNetMon uses this format to export and receive data to/from other instance of FastNetMon. You can find detailed format description here.

FastNetMon can receive traffic telemetry in Tera Flow format or can export it to remote machine. Your own applications can send traffic in this format to FastNetMon.

To configure FastNetMon in client mode you need to apply following changes.

Enable Tera Flow plugin:

sudo fcli set main tera_flow enable

Set host to listen on (we recommend using internal IPs to listen on for production setups):

sudo fcli set main tera_flow_host 0.0.0.0

Set port to listen on (you may specify multiple ports):

sudo fcli set main tera_flow_ports 8104

To apply changes, please use following command:

sudo fcli commit

You can conform that FastNetMon receives traffic from remote end using following command:

sudo fcli show system_counters |grep total_simple_packets_processed

In addition to receive mode FastNetMon can export traffic to remote side using Tera Flow protocol too.

To enable export capability, you can use following commands.

Enable plugin:

sudo fcli set main traffic_db enable

Specify remote host and port:

sudo fcli set main traffic_db_host 10.1.2.3
sudo fcli set main traffic_db_port 8104

If you use traffic capture from mirror / SPAN you can enable sampling to reduce load and mount of telemetry traffic:

sudo fcli set main traffic_db_sampling_rate 512

And apply changes:

sudo fcli commit

To debug issues with traffic export you can use this command:

sudo fcli show system_counters | grep traffic_db

It will show you multiple metrics about any issues happened during export:

traffic_db_errors                        0 
traffic_db_pushed_messages               0 
traffic_db_sampler_seen_packets          0 
traffic_db_sampler_selected_packets      0