To disable all IPv6 traffic on your Mac system:
- Go to Apple - > System Preferences -> Network
- Select the first network connection you see listed on the left-hand side, then click the Advanced button.
- Go to the TCP/IP tab at the top
- Beside "Configure IPv6", set it to "Link-local Only"
- Click Ok to apply the change
- Repeat steps 2-5 for any remaining network connections you see in your Network window.
- Reboot your computer, so all changes fully take effect.