Linux orinoco, wireless, dhcpd setup "gotchas"

[Duncan Thomson]

I spent some frustrating hours getting things working, so I thought I'd pass on
what I learned.

First, Orinoco card firmware 8.10 didn't seem to work in ad-hoc mode with kernel
drivers included in Linux 2.4.7-10.  Nor did it work with drivers included in
pcmcia-cs-3.2.0.  However, it does seem work with drivers included in kernel
2.4.18.  Moral of the story - if you're having problems with Orinoco cards,
upgrade to newer kernel if possible.

Second, there appears to be a timing problem with dhcpd and pcmcia.  I don't
fully understand it.  If you start dhcpd too soon after starting pcmcia, the
ethernet interface for your wireless interface may not be fully "up".  If the
interface doesn't exist at all, dhcpd complains and exits.  However, even if the
interface exists, in some cases dhcpd doesn't seem to listen to it.  It doesn't
complain, but seems to ignore incoming requests on the interface.    I'm not
sure exactly what's going on, but I changed my boot sequence from starting dhcpd
from link in /etc/rc.d/rc3.d/Sxxdhcpd (RedHat startup scripts method) to
starting it in /etc/rc.d/rc.local with "sleep 4; /etc/init.d/dhcpd start".  This
seemed to do the trick.

I can now get my windows laptop to come up and talk to my linux box over
wireless as well as over wired ethernet.  The linux box serves as a dhcp server,
firewall, and NAT box for my cable modem connection to the internet.

Next step: Get IPSEC working to protect the communications between my laptop
(windows and linux) over the wireless LAN to my linux firewall, since I think
there's good reason not to trust WEP.

Duncan