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From: Jeff Liebermann on 29 Jan 2008 13:34
Jennifer R <james.raden(a)gmail.com> hath wroth:

>Thanks for the link to the software. I downloaded it yesterday and
>checked it out. However today my DHCP *is* working from this
>particular coffee shop, so I'll have to wait for the next problem
>before I enlist its aid.

Run it to see how it works. A fun test is to intentionally set you
laptops IP address to some random IP that is guaranteed not to work
with the hot spot. Then, run the DHCP test program. It should still
work (because it uses broadcast packets).

>I *have* tried the /release /renew pairing, many times.

Ummm... it's "repair". "Repairing" is what you do with a BlueGoof
headset or device.

>I usually use
>the "repair" option, which does more than that release/renew -- it
>disables the adapter, clears various caches, etc.

IPCONFIG /flushdns
will clear the DNS cache. However, that's not causing your problem.
My guess(tm) is that since your MAC address is no stored in the
unspecified model coffee shop wireless router's DHCP lease cache
table, it will continue to work at this coffee shop until some other
customers has the same problem, complains to the manager, and they
reboot (or flush) the router. As I think I mentioned, I've created
this situation using DD-WRT which was not fixed with a power cycle
(because the DHCP lease table was saved in NVRAM). You can sorta
verify my guesswork by recording what IP address the DHCP server
delivers at this coffee shop. If it's always the same, then my
guesswork is correct. If it's fairly random, I'm wrong.

>I agree with
>Microsoft's "repair" philosophy -- they clean the slate and start
>over. (I actually met the guy who implemented the XP SP2 wireless code
>for MS, at a national park in Panama of all places. I thanked him
>profusely for the vast improvement over the previous implementation.

I would have cursed him and his accomplises for a variety of
abominations. The most disgusting is that for many years, Microsoft
has promoted the idea that computers have IP addresses. This is
incorrect. Interfaces, such as ethernet cards, wireless cards, cell
phone cards, and such have IP addresses. It took several years and a
few revisions to get that straight. Recently, there was an
un-necessary change in how Vista uses DHCP with accompanying failures
to obtain DHCP leases. The MAC layer network and wireless diagnostics
in W2K and XP are almost totally missing. There have been substantial
improvements with Vista but nothing resembling an industry standard
management protocol (i.e. SNMPv3) that is suitable for monitoring MAC
layer errors (necessary for wireless error detection). Etc... etc...

>I used Wireshark to examine what
>happened during the /renew, and that's when I discovered that the
>router *was* offering a DCHP configuration, but that my laptop was
>ignoring it for some reason.

Dunno. Please don't send me the capture file. I don't have the time.

>I suspect this utility will merely tell me what's in the DHCP OFFER
>packet (a lot easier to use than Wireshark!) but I'll bet that it
>won't actually configure the network adapter.

Correct. All it does it test the DHCP server.

>Still -- a lot better
>than using Wireshark. It will help me limp through. And it's
>definitely a lot easier than having no connectivity.


--
Jeff Liebermann jeffl(a)cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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