In this tutorial, we learn how to fix error code 86420 and change your NAT type to open. First, go to the website to change the settings for your Linksys router. Next, go to the applications tab that says "applications and gaming". After this, go to port range forwarding, then write in a name next to where it says "application name". Under "start" write the number 1 and under "end" write 6553, then keep "both" marked under protocol. Next, enter in the last 3 digits of your console's IP address under where it asks for the address. Now do this for the Xbox by going to settings, network settings, and configure network. When you get to this, click on the "dmz" tab and write the same three digit number under "destination". Now, save your settings and you will be rid of the error code and be able to play your games!