[GTALUG] (question) TP-Link TL-WR802N 300Mbps Wireless-N Nano Router

[Lennart Sorensen]

On Thu, Aug 11, 2016 at 11:52:57PM -0400, William Park via talk wrote:
> Anyone have this one?
>     http://www.canadacomputers.com/product_info.php?cPath=27_1046_365&item_id=087761
>     http://www.tplink.ca/en/products/details/TL-WR802N.html
> If so, have you ever used its "Client Mode" and can you confirm that it
> works?
> 
> I need small portable "wireless bridge", and the advertised "client
> mode" is what I need.  But, last TP-Link I bought was N750 dual-band
> TL-WDR4300.  It advertised "wireless bridge" and even their tech support
> said so.  But, both lied.  Shocking!
> 
> I have Linksys WRT model with DD-WRT, and its client bridge works.  But,
> it's a bit bulky to carry around.

Wireless bridging is actually quite tricky.

Wifi expects connections to an AP to be for ONE mac address only.
This makes doing bridging tricky if you expect more than one device to
use the bridge.  Doing a bridge for a single wired device to allow wifi
is simple, just use the mac address of that device for the connection
to the AP and it will work.  However if you try to do multiple devices
behind one bridge, now what?  The AP will per the standard only allow
traffic from one MAC for a given connection, so either the bridge has
to do MAC address NAT (which is tricky to get right), or you could do
the full layer 3 NAT instead and just handle it that way (which seems to
be the common cheap solution since it actually works and does what most
people want, and allow internet access from clients and nothing else).

Now if you use WDS things get better, but unfortunately it isn't
apparently quite an official standard so it might only work if all the
wifi devices involved are from the same vendor.  WDS can be used to setup
a mesh network of repeaters, or it can be used for bridging and solves
the MAC address issue by adding an extra field to store the MAC address
of the sender in addition to the existing field for the MAC address of
the wifi sender (which would be the bridge device).

Various vendors have had proprietary WDS type things to allow two APs
of the same model to work as a base station and a bridge together, and
they use their own extensions to allow multiple MAC addresses behind
one wifi connection to get through.

This is the same thing that is preventing running a VM in bridged mode
on a laptop with a wifi link.  If you do full NAT you are fine, but if
you are trying to run a VM as a server and make it accessible to the
network you are out of luck.

-- 
Len Sorensen