[svlug] Re: Wireless

joel williams joel at emlinux.com
Mon Jan 20 07:40:17 PST 2003


>
>
>Hi everyone,
>
>I an thinking about installing a WLan. Any recommendations?
>It should work well with my Linux boxes, good but not paranoid 
>security, 
>good throughput, nicely configurable thorugh a web interface, and play 
>well with AT/T Cable.
>I thought about the Netgear FM-114P or the Linksys BEFW11S4 as 
>recommended by
>Toms hardware guide. But I am no sure. 
>Another thought I had was buying a Sun SparcStation 5 for really cheap. 
>Is it possible to integrate it wirelessly ?
>  
>
Pretty much all current generation wireless products will work with 
Linux or Sun.
Just look for something with the Wi-Fi label. The bigger issue is how 
you set up
you network, and what you expect to do with it.  Because you are using 
ATT/Cable
you probably have a PPPoE connection.  In order to share this with 
mulitple computers (whicch
I assume  you want), you can have this gateway terminate the PPPoE 
connection and
have it NAT out to your local  computers. The other alternative is to 
put the  wireless
gateway  into bridge mode, and bridge through  to your Linux box and run  
PPPoE on that, with a second Ethernet  subnet.
While many Linux purists prefer this,
I opine that, for most basic users, the wireless gateway is preferrable 
because:
  1. it is  harder to hack
   2. easier to configure than any Linux/Unix I have ever seen.
  3. uses 1/10 the amount of electricity:  you do not need to keep one 
computer on
      all  the time just to provide gateway services.

Here are some additional thoughts:
  1. if you are not running any servers, (ie: web, telnet, ...) and just 
want to get to the
internet, then you can  use the NAT and firewall built into the wireless 
gateway,
and run your Linux, windows ,etc off of that. This is trival to install 
& operate.
  2. if you want your local machines to talk to each other, then it is 
eaisest to set
them up with static ip  addresses. Linksys supports this, It think 
Netgear does also, but not sure.
They let you assign static IP within the same subnet that they use for 
their built in  DHCP server,
so that NAT will work.
  3. if you want to run servers, these will allow you poke holes in the 
firewall, but this is often
not handled very well, Like FTP only works in pasive mode on some 
connections, and
some (ie: Nortel) VPNs do not work reliabiliy.
  4. if you want to run Linux based VPNs  and some serious servers, use 
Linux as the
gateway rather than the wireless gateway. You have more control and 
flexibility, at a cost
of more administation headaches. (I do this.)

An additoinal suggestion on wireless standards. If you can hold off for 
a few months, I would
wait for 2nd generation 802.11g products. 11g  runs about the same speed 
as  802.11a, and
has better range in some environments. It runs in the same frequency 
band as 11b and shares
many of the same hardware/software components.
You want to wait for 2nd generation because the current products are
pre-standards releases, and there are some changes.
Future interoperability is not guaranteed.  Also be sure that
the product is fully dual band, between  11b and 11g (They should be.)

For the longer term, I would stay away for 11a because there is little 
compelling argument.
.11g runs about the same speed.
(The speed increase is mostly due to using OFDM modulation in both 
standards.)
Right now it is less impacted by interference from wireless phones, etc, 
but this is about to
change, as newer wireless products are now coming out in this same band, 
and I suspect
that the range will degrade faster with the same level of background RF 
noise.

Joel Williams - emLinux





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