|I use Tomato firmware and I just snuck a quick peak. Under Basic network setup there's a box beside "Use WAN port for LAN" that I would check in order to enable this. As to where this setting would be in DD-WRT I can't say as I've avoided their firmware since discovering (the hard way) that it's nearly impossible to remove/replace DD-WRT once you've installed it. I won't support anybody who tries to force you to use their stuff in this fashion. I believe in freedom of choice.|
Is the youtube video even made for your version of DD-WRT firmware? If not, find one that is.
If it is, contact the DD-WRT people and ask them.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.