Dell Wireless 1490 Dual Band WLAN Mini-Card will not get IP address(ignores DHCP OFFER packets)

[Jennifer R]

This is ridiculous. My Dell Wireless 1490 Dual Band WLAN Mini-Card on
a Dell Precision M90 Win XP SP2 just refuses to grab its DCHP address
half the time from public access points. Everyone around me is humming
away with no problem. I've got it configured as DHCP, everything
default, but it doesn't work. During a "repair" or a "ipconfig /renew"
I can see that it does indeed receive a couple of packets, but it's
doing nothing.

If I run Ethereal/Wireshark I see that the DHCP server is sending two
DHCP OFFER packets to my machine, but my machine just ignores them.
This seems to happen in half the public access points I go to (over
which I have no control), and it's inconsistent. Some days it works,
some days it does not.

Do I really have to run Wireshark and dissect the DHCP OFFER packets
to manually configure my Wireless Ethernet card every time? Is there
some mysterious configuration parameter that will help solve this?

Thanks.

- Disgusted with Dell

[Jeff Liebermann]

Jennifer R <james.raden@gmail.com> hath wroth:

>This is ridiculous.

What is rediculous? The problem or the question?

>My Dell Wireless 1490 Dual Band WLAN Mini-Card on
>a Dell Precision M90 Win XP SP2 just refuses to grab its DCHP address
>half the time from public access points.

Let me guess. This only happens when you've successfully used your
laptop at your home or office, and then go to a coffee shop?

>Everyone around me is humming
>away with no problem. I've got it configured as DHCP, everything
>default, but it doesn't work. During a "repair" or a "ipconfig /renew"
>I can see that it does indeed receive a couple of packets, but it's
>doing nothing.

This is sounding familiar. You're close.

>If I run Ethereal/Wireshark I see that the DHCP server is sending two
>DHCP OFFER packets to my machine, but my machine just ignores them.
>This seems to happen in half the public access points I go to (over
>which I have no control), and it's inconsistent. Some days it works,
>some days it does not.
>
>Do I really have to run Wireshark and dissect the DHCP OFFER packets
>to manually configure my Wireless Ethernet card every time? Is there
>some mysterious configuration parameter that will help solve this?
>
>Thanks.
>
>- Disgusted with Dell

Right. Let's blame Dell. The first step to solving a problem is to
blame someone. Dell will suffice for now.

I'll assume that the coffee shop is not running out of DHCP addresses.
I created this problem at some of my coffee shop hot spots using
DD-WRT by specifying that DHCP save the leases in NVRAM. That worked
until I filled up all the slots, where it decided that it didn't want
to add any more clients.

You were close. Try this next time:
Start -> Run -> cmd <enter>
ipconfig /release
(wait a few seconds)
ipconfig /renew
ipconfig (to display the results)

What is happening is that Windoze XP SP2 thinks you're still at home
or work and is trying to renew the previously assigned IP address
forever. This is especially true if the IP address of the access
point is the same at work, home, and at the coffee shop, a common
problem. The DHCP requests are done with MAC broadcasts, but the
renewals are done using IP addresses.

This was fixed in some obscure wireless networking update from
Microsoft. It was also an issue with some wireless clients and
drivers. Check if you have the latest drivers and wireless updates.

You might also wanna try a DHCP tester at:
<http://www.weirdsolutions.com/weirdSolutions/files/products/desktopSoftware/desktopQueryTool/querytool_free.exe>
There's a bit of a trick to using it. Type in literally anything into
the "Device Identifier" field. Check the "Request response" box.
Don't check the "Use BOOTP" box. You do NOT need to be connected for
this to work. Mine returns:
option PKT:Opcode=2
option PKT:HType=1
option PKT:HLen=1
option PKT:Hops=0
option DHCP message type=5
option PKT:Flags=32768
option PKT:Seconds=0
option PKT:XID=41
option PKT:SName=
option PKT:Boot file=
option PKT:CIAddr=0.0.0.0
option PKT:YIAddr=192.168.1.100
option PKT:SIAddr=192.168.1.1
option PKT:GIAddr=0.0.0.0
option PKT:Magic cookie=99.130.83.99
option Subnet mask=255.255.255.0
option Gateways=192.168.1.1
option Domain name servers=192.168.1.1
option Broadcast address=192.168.1.255
option Server identifier=192.168.1.1
option DHCP address lease time=7200
option DHCP renewal time=3600
option DHCP rebinding time=6300
option PKT:CHAddr=00
which is rather interesting as the machine I'm running it on has a
static IP address. Also, the results are rather "interesting" if the
coffee shop has more than one DHCP server running.


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

[Jennifer R]

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.

I *have* tried the /release /renew pairing, many times. I usually use
the "repair" option, which does more than that release/renew -- it
disables the adapter, clears various caches, etc. 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.
He probably gets that a lot.) 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.

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

On Jan 27, 12:29*pm, Jeff Liebermann <je...@cruzio.com> wrote:
> Jennifer R <james.ra...@gmail.com> hath wroth:
>
> >This is ridiculous.
>
> What is rediculous? *The problem or the question?
>
> >My Dell Wireless 1490 Dual Band WLAN Mini-Card on
> >a Dell Precision M90 Win XP SP2 just refuses to grab its DCHP address
> >half the time from public access points.
>
> Let me guess. *This only happens when you've successfully used your
> laptop at your home or office, and then go to a coffee shop?
>
> >Everyone around me is humming
> >away with no problem. I've got it configured as DHCP, everything
> >default, but it doesn't work. During a "repair" or a "ipconfig /renew"
> >I can see that it does indeed receive a couple of packets, but it's
> >doing nothing.
>
> This is sounding familiar. *You're close.
>
> >If I run Ethereal/Wireshark I see that the DHCP server is sending two
> >DHCP OFFER packets to my machine, but my machine just ignores them.
> >This seems to happen in half the public access points I go to (over
> >which I have no control), and it's inconsistent. Some days it works,
> >some days it does not.
>
> >Do I really have to run Wireshark and dissect the DHCP OFFER packets
> >to manually configure my Wireless Ethernet card every time? Is there
> >some mysterious configuration parameter that will help solve this?
>
> >Thanks.
>
> >- Disgusted with Dell
>
> Right. *Let's blame Dell. *The first step to solving a problem is to
> blame someone. *Dell will suffice for now.
>
> I'll assume that the coffee shop is not running out of DHCP addresses.
> I created this problem at some of my coffee shop hot spots using
> DD-WRT by specifying that DHCP save the leases in NVRAM. *That worked
> until I filled up all the slots, where it decided that it didn't want
> to add any more clients.
>
> You were close. *Try this next time:
> Start -> Run -> cmd <enter>
> * *ipconfig /release
> * *(wait a few seconds)
> * *ipconfig /renew
> * *ipconfig *(to display the results)
>
> What is happening is that Windoze XP SP2 thinks you're still at home
> or work and is trying to renew the previously assigned IP address
> forever. *This is especially true if the IP address of the access
> point is the same at work, home, and at the coffee shop, a common
> problem. *The DHCP requests are done with MAC broadcasts, but the
> renewals are done using IP addresses.
>
> This was fixed in some obscure wireless networking update from
> Microsoft. *It was also an issue with some wireless clients and
> drivers. *Check if you have the latest drivers and wireless updates.
>
> You might also wanna try a DHCP tester at:
> <http://www.weirdsolutions.com/weirdSolutions/files/products/desktopSo...>
> There's a bit of a trick to using it. *Type in literally anything into
> the "Device Identifier" field. *Check the "Request response" box.
> Don't check the "Use BOOTP" box. *You do NOT need to be connected for
> this to work. *Mine returns:
> * option PKT:Opcode=2
> * option PKT:HType=1
> * option PKT:HLen=1
> * option PKT:Hops=0
> * option DHCP message type=5
> * option PKT:Flags=32768
> * option PKT:Seconds=0
> * option PKT:XID=41
> * option PKT:SName=
> * option PKT:Boot file=
> * option PKT:CIAddr=0.0.0.0
> * option PKT:YIAddr=192.168.1.100
> * option PKT:SIAddr=192.168.1.1
> * option PKT:GIAddr=0.0.0.0
> * option PKT:Magic cookie=99.130.83.99
> * option Subnet mask=255.255.255.0
> * option Gateways=192.168.1.1
> * option Domain name servers=192.168.1.1
> * option Broadcast address=192.168.1.255
> * option Server identifier=192.168.1.1
> * option DHCP address lease time=7200
> * option DHCP renewal time=3600
> * option DHCP rebinding time=6300
> * option PKT:CHAddr=00
> which is rather interesting as the machine I'm running it on has a
> static IP address. *Also, the results are rather "interesting" if the
> coffee shop has more than one DHCP server running.
>
> --
> Jeff Liebermann * * je...@cruzio.com
> 150 Felker St #D * *http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann * * AE6KS * *831-336-2558

[Jeff Liebermann]

Jennifer R <james.raden@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@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558