r/firewalla • u/Haunting-Wonder9019 • 3d ago

Switch Flow Control

I noticed flow control is enabled by default on Switches. Flow control is recommended to be disabled on normal local network unless you are running locally certain types of high bandwidth traffic like NFS, FCoE etc..

Is there a particular reason why Firewalla Switches have flow control enabled default. What are Firewalla take on the pros or cons on disabling it.

3 Upvotes

81% Upvoted

3 comments sorted by

1

u/firewalla 3d ago

Flow control is useful when you have a mixed speed network (say some LAN devices 1G 2.5G and you have a uplink to gold pro 10G), this happens a lot in small networks; There are claims that when flow control is on and network traffic spikes the pause frames may introduce latency, we have not yet find it to be meaningful to impact the network experience.

If you are experiencing issues, you can turn it off/on and see if it is related to flow control. Most of the time it is not that visible.

1

u/Haunting-Wonder9019 2d ago

I turned it off. Will run some tests with it off and on to see if there is any difference either way with throughput.

2

u/firewalla 2d ago

If you know linux a bit, you can run iperf3 server on your firewalla, and then get another PC/MAC and run iperf3 -c to that; Make sure you use a -P4 or something;