No it's not.

(Unless the person hosting has zero understanding on how a basic LAN works, and didn't invite a guest who knows. At that point, they should be re-thinking what they are doing)

We did exactly that at the last BO LAN earlier this spring.

One 16 port switch and a wireless bridge in one of the ports.

Done!

Also did the same thing at my HBOLAN. Router into one port on the 16 port switch- clients into the rest.

Done!

And that's exactly what everyone did- while we played H3, H4 and Reach, we all appeared to be online. We were in custom games, but still visible to XBL.

Essentially we did the "hand shake" or "check in" and it wasn't even required at that point.

Technically anyone could have joined us too, (though having 14-16 people routing out through one home grade line would = terrible quality I'm sure) if they wanted. So Snipe could have been at HBOhio or the Smokey Mountain LAN from afar.

: It's stupid.

The world we live in is always on now. Stupid? Maybe. Is what it is Mr. Miller. Dev's and publishers want their games to call home now.