[Balug-talk] Trying to demystify Wireless networking...

[moseley at hank.org]

On Sat, Aug 16, 2003 at 06:04:44PM -0700, Tom Carroll wrote:
> Would I only need the Wireless Access Point if my entire network were
> running on wireless?

I have an AP just hung off a port on my switch for my internal network. 
In other words, a Linux firewall/NAT machine that connects to a switch
with most machines hard wired to the switch, but also an AP connected to
a port on the same switch.  Works just like the wired setup, really.  My
wireless machines were on the same segment as everything else.

(Someday I want to try out a bridging firewall setup and move the NAT 
to another machine.)

I suppose the AP is acting as a bridge.  I hadn't thought about it much
since it just works.  My AP has it's own IP (for management) and MAC I
suppose, but when I connect from my laptop its MAC address is sent
because I've got DHCPd to assign the IP address based on MAC.  I think
that's how it works.

I have dhcpd assign "static" IPs because I have bind setup using "views"
to handle DNS for my internal LAN and I wanted "static" IPs for my
internal machines.  There's a nice program (is it dnsmasq?) that will
actually use the leases file for internal DNS lookups -- so you can have
changing internal IPs and still do lookups.

> How would the DHCP work - will my SME box still
> handle the DHCP or will the WAP do all this from now on (basically like
> a wireless switch)?

As mentioned above, I have one DHCP server that assigns IPs for all my
machines, including wireless.


> Do I even need a WAP?  Can I just install an
> 802.11g PCI card in the SME box and let it communicate directly with the
> wireless LAN, just like it does right now with the wired LAN, and handle
> all the DHCP and traffic, without a switch?

Good question.  Seems like a lot of the low end APs often just have a
PCMCIA card in them.  APs' are not that much more money.  I also 
remember seeing some page about running linux on something like a WAP11, 
although my goggle luck isn't good at the moment.  It was interesting.

BTW -- I think I'm using an SMC AP at the moment. I've got two PCMCIA
cards -- one SMC and another and Aironet 352 (IIRC).  When I use the
Aironet the SMC AP locks up after a short time.  Never have figured out
what is happening.  Firmware is up to date on both the Aironet and SMC
AP, so not sure where else to look.

This is also an interesting read:
  
http://www.oreillynet.com/pub/a/wireless/excerpt/wirlsshacks_chap1/index.html

-- 
Bill Moseley
moseley at hank.org