[Discuss] Use Linux laptop as wifi router? Is that even the right solution?

[tmetro+blu at gmail.com (Tom Metro)]

David Kramer wrote:
> Change my laptop's MAC address temporarily to that of the Roku,
> authenticate, then try to connect with the Roku.  Sounds reasonable,
> except that it didn't work.

This is probably worth revisiting. In theory it should work. Perhaps
test it after you have returned home and can then use other machines on
your LAN to verify whether you were successful in switching your MAC.

Even if you did everything correctly, there are some reasons why it
might not work. After you've authenticated with the laptop, you
presumably disconnect it, and power up the Roku, which will initiate a
new DHCP handshake. The hotel's authentication system might take note of
that and insist on repeating the authentication. Or if it is
sophisticated, it might notice the Roku identifies itself differently in
the DHCP request, or otherwise has a different "signature" than the
previously authenticated device.


> Add a USB WiFi stick onto my laptop and set it up as a
> router...but I would have to bring it with me.
> 
> Pick up a travel router and use it to NAT.  This option really only
> works if the hotel has wired internet...

If you don't want to be dependent on carrying the laptop with you, your
best bet is probably the travel router. That alone, for the scenario you
say is most typical (wired connection to the hotel), should do the trick.

I gather the Roku is WiFi only.

To support the WiFi-to-WiFi routing, I'd look for a travel router that
1. is supported by OpenWRT or DDWRT, and 2. has a USB port to plug in a
2nd WiFi radio. Then set up the USB adapter as the WAN port and set the
built-in radio to a different channel.

If you can't find a travel router meeting that criteria, even full size
consumer routers aren't much bigger. One that's a few years old could be
picked up on eBay and would do the job.


> I also have a WRT54G I'm not using that I could test it
> out with before buying something smaller.

That should do the trick for the wired scenario. No USB ports for the
other scenario. (I'm not familiar with the "half-duplex" trick you
mentioned that could be done with a single radio. Sounds like a bad idea
for connecting a video streaming device.)


> I see differing information on whether the hotel network will see one
> MAC address or each device's MAC address.

If the router is in routing mode (as implied by NAT being active), then
by definition it is isolating the LAN and WAN Ethernet segments from
each other, and the MAC addresses on the LAN side aren't visible to the WAN.

 -Tom

-- 
Tom Metro
The Perl Shop, Newton, MA, USA
"Predictable On-demand Perl Consulting."
http://www.theperlshop.com/