Re: [tlug] wireless router: beginner advice

[Dan Burrowes <danburrowes@example.com>]

Hi Darren


On 09/10/2010 04:55 PM, Darren Cook wrote:
> Any thoughts on this, BUFFALO 11n/g/b対応 無線LANルーター Air Station
> WHR-G301N, 5000 yen: http://www.amazon.co.jp/dp/B002X79784 [1]
> 
> Or this one, Planex FFP-PKR01, for just 3000 yen:
>   http://www.amazon.co.jp/dp/B003WMAZ8K

The two models you mentioned are really designed for different purposes:
the Buffalo better serves as a home router/access point/switch, whereas
the Planex is best as a travel device for on-the-spot wireless network
needs.


> I'm a bit vague on wireless LANs. Do I simply plug it in to my home LAN
> hub [2], and can then connect linux, windows and other devices that have
> a wireless LAN card in them? 

The simplistic answer is "yes", although there are some issues you would
certainly want to deal with, such as making sure that WPA2/PSK is in use
(and depending on your paranoia, WPA2/802.1X).  As long as the PC's
wireless card's hardware supports WPA2, then the drivers should be up to
date enough, and you'll be good to go.  For Linux, cards with an Atheros
chipset tend to have the best support via the open source "ath5k" and
"ath9k" drivers (former versions were called "MadWifi").  Please do note
that most of these wireless routers are just that: routers.  By default,
when plugged into a switch, they will create a new network for the
devices behind them.  Since they also typically are not running routing
protocols by default, that can create configuration issues if you want
the networks to be able to talk to each other.  Regarding option [2],
which you noted, these devices also run their own rudementary packet
filters (firewalls, if you will), which are not up to snuff compared
with iptables or pf.  The other option (which I personally use), is to
change the router's firmware to OpenWrt, which is an open source,
embedded Linux.  Practically anything that can be done on a Linux system
can be done on OpenWrt, and it is very well supported.  You'd want to
make sure that the hardware is compatible, however.  I'm not familiar
with your network topology, so I can't comment on what state this would
leave your samba server in.


> It gives a list of OSes it works with,
> naturally not a mention of linux, but I'm puzzled where an OS fits in.
> I assume I configure it somewhere to tell it where the gateway IP? And I
> guess it can also be configured by DHCP, and provides some rudimentary
> firewalling of its own? And I assume they all come with proper
> encryption options, that are genuinely good assuming configured
> properly? (I.e. are those all standard features I should expect on any
> wireless router, or do I need to be studying specs and comparing models
> carefully?)

Hmmm...I kinda jumped the gun there and touched on a few of these
questions above, but as far as the OS compatibility it's because both of
the vendors provide host-based software applications which can "assist"
you in configuring the device (for example, automating the setup of
WPA2/PSK for wireless).  The devices do not require this software --
indeed, most of the detailed configuration takes place via a web-based
interface.  As it stands, WPA2 with 802.1x authentication is the
strongest you can get, and most devices have supported this for a few
years.  Please note that WPA2/PSK is broken, but it's still good enough
for home use, assuming you are not a high-profile target for attack.


> My house is two floors. What part of the spec do I need to look at to
> know the range of these routers? (One of the comments on the Buffalo
> model says 60 tsubo house, and the signal is fine upstairs and through 2
> walls.)

Unless your house is huge and/or made of reinforced concrete, you
shouldn't worry:  two floors should be fine.  Like any Radio Frequency
(RF) device, the range is determined by the wattage of the sending and
receiving antennas.  With vendor-supplied drivers and configuration
software, however, these are largely non-configurable.  Within Linux,
however, the wattage can be adjusted.  Unless you are very familiar with
RF concepts, however, I would recommend leaving this alone since
increasing power also increases noise, and you have to carefully balance
the two.  Remember also that RF doesn't cut off with distance; it fades.
 Similar to getting radio reception in your car.  With 802.11
technology, reception quality = speed.  This means that you're unlikely
to simply *not* be able to get *any* signal in your house.  Any
degradation in reception will merely result in the 802.11 connection
becoming slower as the reception gets worse.  Scan for neighborhood
wireless networks with a laptop, and you'll likely find that you can
pick up the Tanaka's wireless network from down the block.  If you
connected to it, the speed wouldn't be so great, but you *would* be able
to connect.  If you want to simulate this, use two laptops, and
configure one of them as an ad-hoc network or access point.  Then try to
connect with the other laptop.  Laptop wifi card output power isn't as
strong as a dedicated access point, but you'd be able to sort of
experience what you'll be getting into.

--dan