i did the exact same thing on my router TP-link WR842ND and it worked the first time! then i changed the DNS servers from my router and i restarted it in order for the changes to be applied but it did not connect anymore! i revert the changes (DNS servers) but still no connection!

I reset the router and I did all the steps again! still nothing!

in the router log it says cannot authenticate ourselves with peers and also LCP down!

what can be the probem?

I tried the steps 100 time!

the 621 is on LAN 3 binded! everything is exact with this tutorial!

can u help me plz
thanks