[kwlug disc.] need some opinions on a misbehaving wireless network

[John Van Ostrand]

On Mon, 2007-06-18 at 15:50 -0400, Robert P. J. Day wrote:
>   i have, of course, done all the standard stuff -- resetting the
> modem and router, trying to troubleshoot whatever i could think of,
> but to no avail, and the maddening thing about this is that the
> problem is unpredictable -- a web page that was unreachable will, five
> minutes later, be reachable, while some other page is now gone.
> 
>   at this point, i'm seriously starting to consider hardware, and i'm
> taking in a couple new routers when i visit tomorrow, since i can't
> imagine what else it could be by now.
> 
>   does any of this sound familiar?  any other bits of advice?  thanks.

To determine if it's DNS related try the IP addresses alone. It may not
result in the same web page but if the browser can hit a site then you
know DNS is the issue.

You mention WAP but is it the firewall too? 

I know that some of these firewalls (like LinkSys) will operate in a
different way depending on circumstances. If the LinkSys knows the DNS
server addresses (because it is connected to the Internet and has taken
them from DHCP or PPPoE) then it hands those to the PCs via DHCP. If it
doesn't know the DNS (because it's not connected) then it hands its own
address and then it acts like a proxy.

I've seen cases where the proxy functionality doesn't work as expected
and this may be the problem that you are seeing.

Check the DNS settings on the PCs ("ipconfig /all" for windows) and make
sure the DNS looks like the ISP's. If not do an "ipconfig /release" and
"ipconfig /renew" to  re-lease an address. If you're VNC'ed or RDP'ed in
then you'll have to get the user to do it.