How do you measure throughput on an OpenWrt device?

I am making various configuration changes and would like to do basic measurements of network throughput so am I confident of not introducing performance regressions.

But I am at a loss for how to measure simply and accurately!

What techniques and command line tools do you use to measure throughput or network performance? Thanks!

perf3 works very well for this ?

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Thanks for the tip! I noticed the utility and package is iperf3
I installed it with:

opkg update
opkg install iperf3

You generally don’t want to run it on the router itself as it’s going to give skewed results trying to route at full speed and generate traffic as well.
You want a device on the wan and on the lan side and running iperf between those.

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Iperf3 for lan tests and for wan speedtest.net (or fast.com or other internet tests)

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Internet speed test aren't really reliable, because there's no speed and bandwidth guarantee out there.

Iperf3 is a synthetic test, but works well, if setup as described by @lantis1008.

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For me speedtest and fast.com are more than 90% reliable. It a lot better than wasting time to setup 2 hosts and reconfigure openwrt for this.

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Thank you everyone for the nice tips!

I want to confirm I understand this so am detailing my network topology and how I should set this up.

My openwrt router connects to a pfsense box using the WAN port.
Then, I am plugging my devices into the openwrt box's LAN ports.

Thus, I would run

  • iperf3 -s on the pfsense box
  • iperf3 -c <pfsense box ip address:port> on the device connected to a LAN port

This sound correct?

yes, and the pfsense LAN subnet have to differ from the one on the router.

thanks! My openwrt box's dnsmasq is running but forwarding DNS.
Thus, it hands out 192.168.1.x addresses.
The pfsense box is on the 192.168.30.x subnet.

So it sounds like I should be able to get a general idea of network performance with this approach.

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