[NCLUG] Perplexing wireless issue - Voodoo accepted

[dann frazier]

On Sun, Feb 07, 2010 at 06:33:35PM -0700, Paul Hummer wrote:
> Hey NCLUGers-
> 
>   I have an issue with my home wireless I thought you all might be able to help
> with.  Yesterday morning, I checked my email and then went out for two hours.
> When I came back, NetworkManager was spinning trying to find the network.
> Here's where I'm at?
> 
>   First, the setup: I have a WRT54GL with Tomato 1.25 running on it.  The
> laptop in question is a Thinkpad T61 with an Intel Wireless 3945 PCI card.
> 
>   Next, the quest for a solution: I first tried turning it off and turning it
> back on again. <it-crowd-joke> I reset the cable modem, router, and rebooted my
> laptop.  That didn't fix it.  My other devices were working fine on the network
> (PS3, Xbox, other laptops/desktops).  So I then reset the router to Tomato
> defaults.  Nothing.  I then hooked up another router through the WRT54GL (a
> Buffalo WHR-HP-G54 with dd-wrt) and then laptop connected right up.  I then
> re-flashed the WRT54GL with Tomato 1.27.  The laptop wouldn't connect.  I
> re-flash the WRT54GL with dd-wrt 24SP1 and the laptop wouldn't connect.  I
> flashed back to Tomato 1.27.
> 
>   The logs on the laptop indicate that it sends the DHCPREQUEST but receives no
> DHCPOFFER.  The logs on the router indicate a DHCPOFFER was sent, but no
> DHCPACK is received. I tried using wireshark and tcpdump to see if the laptop
> was just ignoring the DHCPOFFER packet.  I couldn't get anything conclusive,
> but maybe my flags were wrong, or I wasn't looking close enough.
> 
>   Here's where it gets weirder.  I changed the MAC address of wireless
> interface on the WRT54GL, because it seemed MAC related.  No joy.  That was all
> last night.  I started writing this email this afternoon, and thought "What if
> I change my laptop wireless interface NIC?"  So I did it.  NetworkManager gets
> an IP.  About 5 seconds later, NetworkManager then loses the connection.  If I
> change my MAC again, it connects, then loses the connection shortly after.

Bad hardware? I had similar problems when my first WRT54GL fell over.
My current one runs just fine - latest Tomato, and a 3945 in my laptop.