Note: This method is now outdated. Even though it stops lag it does so by distributing bandwidth equally underload. There is probably a way to turn on fq_codel in pfsense but since I don’t have a pfsense box anymore I can’t show you how. You could try following this thread on reddit: https://www.reddit.com/r/PFSENSE/comments/9f46xn/rookie_step_by_step_for_setting_up_fq_codel/
Actual guide (Old)
These are the final steps you need to do for your pfSense box. Doing these following steps will bring you to lag free paradise. After you finished doing this you will no longer lag no matter how much people in your household stream videos, download torrents, and doing those Steam downloads. This is the magic pill and I would like to thank foxale08, my hero, on the pfsense forums. If it wasn’t for this guy I would have never ended my search for the best QoS or way to manage my bandwidth.
Link to the post: https://forum.pfsense.org/index.php?topic=63531.0
If you want to have a successful LAN party you got to have the bandwidth management down. These are the things you need to do in pfSense so that when your internet is under load bandwidth is divided evenly between computers. The great thing about this is that if the internet is not under load and only one computer is using it, it will get all the bandwidth. It’s a much better alternative than limiting the bandwidth each computer can use. It’s dynamic and only divides bandwidth when more than one computer puts the network under full load.
If you need testimonials other posters have reported major successes with this.
First head to the Firewall tab in the 192.168.1.1 page of your pfSense box. then click the Traffic Shaper tab.
After that with the screenshots below created by foxale08.