[Talk] dd-wrt

[flux.simicich at spamgourmet.com]

I'm fairly impressed with DD-WRT, the freeware version of Linux based
router software.

I had a Zyxel wifi router-switch-ip thing that was supplied by the
telco.  I had decided that my laptop was dead, since it was constantly
failing to keep a wi-fi attachment up - but then again, I was having
some other issues.  I finally said, hmmm. The telco had left me two
switches, little boxes that could do nat or bridge, but which didn't
have the wi-fi AP, and also didn't have some of the advanced filtering
stuff that the "triple threat" AP/NAT/DSL Modem things had.  I put
them in as plain bridges.

And I installed DD-WRT in a 54GL.  Now my wi-fi works reliably. It ran
for days - and I guess I blame Zyxel rather than the laptop.

But the connectivity in my bedroom was not so good, in that it refused
to reliably make a connection to cellphones that were running wi-fi,
because of the signal strength.

DD-WRT supports a huge variety of routers, of different brands - I
guess because many of the routers in the world are using the same
cheap hardware, and the small differences between those routers isn't
a big deal to a programmer who is moving one of the industry standard
platforms to their hardware and who has only one platform to
support...but the guys who are supporting DD-WRT are supporting many
of the little minor variations, the obsolete hardware, and so forth.

My first DD-WRT router was a WRT54GL, which was sort of like the very
early WRT54G models, the ones that ran Linux from the factory, and it
took a small bit of special procedure to run get the load installed.
I have no idea why, but you have to install a mini load before you
install the full sized load.  The GL runs Linux internally from the
factory and has as much internal storage as the original Version 1
routers that were shipped with Linux from Cisco/Linksys.  (The newer
WRT54G routers have half the storage that the Linux models had).

The second router I installed DD-WRT on was a WRT54G-TM.  This router
requires another two step install. Step one was a special download
program that essentially wiped the memory - because it was the special
version of the router that had some code that T-Mobile required to do
QoS (Quality of Service) prioritizing as well as power reduction
(telling the phone that it can use less power, I guess), and this
special version of the router was built by Cisco for T-Mobile and I
guess that the special code stopped you from overlaying the router's
firmwear with ordinary firmwear. I presume that it is because T-Mobile
does not want the router running a regular load - at least partially
because the router, as far as I can tell, was always sold with a
subsidy.  (Oddly enough it has twice the memory that the L model has).
This might be one of the best of the B/G router/APs. But someone had
written a pre-loader that took about 5 minutes to overwrite all the
flash, I guess, and then I could download a regular DD-WRT loadout,
but only using tftp.

The reason I wanted a second router running DD-WRT is that I wanted to
hook the routers together using WDS.

There is a standard feature that is supported by many routers called
"WDS".  Stands for "Wireless Distribution System".

You set up the routers to use the same networks, and you set them up
to use the same security and the same passwords and the same SSIDs.
(Or, if this is an open, unsecured mesh, like if everyone in a
neighborhood is willing to share their IP connections you can use the
different SSIDs.  But each router has to know its neighbor's MAC
address - if it is a mesh, the router has to know the mac of anyone
they are to connect to - all their neighbors have to be known.)

In my case, this was a situation where I wanted to extend a secured
net. So both routers use WPA, same key, same ip addresses, and they
bridge. One is the DHCP server, and the other responds to DHCP but it
just reflects the request back to the main DHCP server.  Supposedly,
if you are running in bridge mode there is no reason to do that.  But
it works.

And that is it.  The "server" is the router that has two interfaces to
the outside, while the "client" has no interfaces to the outside.
Thus it runs in "router" mode rather than "gateway" mode, and does not
nat or filter. The router bridges what used to be the WAN interface
connection to the 4 port switch and that is it. It started bridging
across the wi-fi connection and when I turned on wi-fi on my phone
(which is physically far from the first router but close to the new
router) it had 5 bars instead of one bar, and it was able to download
at about 6000 kilobits (to the phone, mind!) on a speed test
(speedtest.net - ookla was the author on Android marketplace if you
are looking to determine which of the several speed tests it is).  I
presume that the wi-fi is not the limiting factor there, but it might
be, since it is going to talk to the other router in G and to my phone
in B.  You lose half the speed when you are on the second link, so 1/2
the transmission time is gone moving data at 6000 kilobits to the
phone in B, as far as I can tell.


I am really impressed with the dd-wrt stuff - the variety of physical
boxes that it supports is amazing to me.  There are people who have
trouble with it, but I have not - I do read the instructions and where
it says to wait, I check my watch and wait.  When it says to hold the
reset button for 90 seconds continuously, I don't second guess, I just
do it.  They warn you over and over again that, 'You can brick routers
by impatiently saying, "This is taking too long, let me power cycle
it,"' and interrupting some time critical process.

And so far the routers have come back, with working DD-WRT loads on
them, after I install the upgrades and to the waiting. I just follow
the instructions, even if they don't make sense to me.

But I was surprised as to how well the config worked with the WDS.
And, of course, if there is something that you can't do from the web
console you can ssh in - after all, it is Linux and it runs scripts -
all that stuff you are familiar with. :-)


But If someone wanted to, say, share the load with their neighbor so
that they would both get wi-fi and pay one fee, find it hard to
imagine a loadout that would work better.

And, as someone pointed out, suppose you trusted your neighbors, and
suppose you all bought a WRT54GL (not that expensive) - it would not
be that hard to hook things up into a mesh

-- 
Life is too short to eat an egg white omelette.  Fucking oatmeal
tastes better.  Order that. Only jackasses order egg white omelettes.