Hi Al,
Here is a repost of a message Carl DaVault sent out to
microsoft.public.windows.networking.wireless concerning using hidden SSIDs.
Chris Gual [MSFT]
--
This posting is provided "AS IS" with no warranties, and confers no rights.
---------- forwarded message ----------
First, make sure your AP and your wireless NIC's have the latest firmware
and drivers.
Next, unhide the SSID and make sure everything connects properly. Does
re-hiding the SSID make the problem re-appear?
If so, it might still be a driver issue.
A couple of things to note about "hidden" SSID's.
- If you are using them, then they are likely not hidden if a hacker wants
to see them.
- Windows tries hidden SSID's "last", so connecting to them may be slower
than to visible SSID's
- Some drivers have had problems connecting to hidden SSID's, so the
experience varies by NIC/driver
(what NIC/driver are you using?)
The way Windows handles hidden SSID's is this:
* It walks through your list of configured networks and tries to connect
to any ones that it can see.
* Then, if it didn't get connected or can't see any visible networks, it
tries each configured network anyway (in case it is hidden).
* It tries to connect by telling the NIC to use specific settings (SSID,
WEP, etc.) for the network.
(at this point, it is up to the NIC to do the actual
association, which is why I think it's a driver issue)
* Windows repeats this process until you are connected - you'll see
balloons letting you know when new networks are visible.
So if everything works with a visible, but not a hidden SSID, it might not
be a Windows problem. On the other hand, if you have a lot of networks
configured, windows is trying them one by one so it may just take a while to
connect - you can try moving the hidden network to the top of your list of
SSID's so it is tried first.
Hiding an SSID doesn't buy any security from hackers and you can use MAC
filtering to block regular people from connecting to your network even if it
is visible. I would recommend making your network visible since it will
improve your connection experience and doesn't hurt security. Even hidden
AP's and their clients are still blasting packets everywhere - it's just
that the beacon packets from the AP don't have an SSID in them. The AP will
still answer to the probe request for the SSID - the probes and responses
will also be visible to hackers.
- Carl
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"Al Blake" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Possible breakthough today:
> Turned *on* SSID broadcast on the access points and suddenly all the
> machines that were giving problems can connect - with full authentication
> and encryption. Strangely enough this works even when the 'broadcast' SSID
> is *not* the SSID we end up connecting to...its early days yet but thetre
> looks to be som wierd combination of card + SP2 + encryption here that
> causes everything to fall in a hole when broadcast is not on.
> Anyway - we use better security that just hiding the SSID
so Im gonna
> leave it on for a week or two and see if its stable.
> Al.
>
>
> "Ron Lehner" <(E-Mail Removed)> wrote in message
> news
(E-Mail Removed)...
>>I have to agree that post SP2 the wireless connectivity of XP has
>> become useless unless you want an unsecure network. I had some
>> wireless clients working correctly for about a week then the following
>> occurred. Only thing added to OS was the updates. I have not went as
>> far to see if any of the updates have caused the problems. But to work
>> for a week then quit, leads me to suspect that is the problem. Here
>> are my problems below.
>>
>> 1 - IAS access was granted and IP address was issued with XP SP2 still
>> indicating it was acquiring network address. WAN and LAN was
>> accessible, but connection dropped out after a couple minutes.
>>
>> 2 - IAS access was granted and DHCP server broadcast ip address with
>> XP SP2 never ack-ing...timed out with 169.xxx.xxx.xxx address.
>> ipconfig release and renew with same results.
>>
>> 3 - Setting alternate config in network settings never worked
>>
>> 4 - IAS access granted, DHCP address accepted, XP SP2 reconnects every
>> 4 seconds.
>>
>> 5 - with encryption off XP SP2 is happy and works fine.
>>
>> 6 - Modify registry not to auto config - set alternate config doesn't
>> work. Result - constantly acquiring network address.
>>
>> 7 - Any encryption, user password auth, certificates, in other words
>> anything to try and protect your network, XP SP2 fails.
>>
>> With this pattern I can not get a grasp on what is causing the
>> problem. Again, I'll look at the updates from the initial install of
>> XP2.
>>
>> Using linksys, buffalo, netgear, and orinco cards all have the same
>> results.
>>
>> I have not found any solution other than to go back to SP1. I am
>> fortunate I never had put this into a production environment.
>>
>> By the amount of posts on this subject, it looks like there are plenty
>> of people with this problem. I would be interested if anyone finds a
>> solution. I have been trying to correct this problem for over a
>> month.
>>
>> End of venting,
>>
>> Ron
>>
>>
>>
>>
>> On Sun, 17 Oct 2004 06:48:56 +1000, "Al Blake"
>> <(E-Mail Removed)> wrote:
>>
>>>We have just migrated 600+ machines to SP2. Needless to say before we
>>>started on this we carried out *extensive* testing of our systems...and
>>>everything passed. A week later we are finding that we are having huge
>>>problems connecting a specific machine/WLAN card combination to our WLAN.
>>>These machines were used on the WLAN for over a year in SP1 without
>>>problems
>>>and given the number of other posts it seems SP2 is the issue:
>>>
>>>Symptoms: Machines associate but never get and IP lease. The access point
>>>is
>>>quite happy and reports no errors. The machines sit there saying
>>>'Acquiring
>>>network address' until eventually they time out.
>>>Configuration: Toshiba Satellite 1800 + Toshiba mini PIC Wireless LAN
>>>card.
>>>AP: Cisco 1200/350
>>>Setup: Static Open WEP OR PEAP-TLS
>>>
>>>We get the same results for both access points and both types of
>>>authentication unless we turn off encryption - then everything is fine.
>>>But
>>>of course no encryption on the WLAN is a non starter.
>>>
>>>Other machine combinations:
>>>IBM T40 + IBM 802.11b
>>>IBM T40 + IBM 802.11a/b/g
>>>Tosh Sat 1800 + Atheros 802.11a/b/g
>>>all work fine.
>>>
>>>So it seems to be a specific combination of SP2 + THIS card + encryption.
>>>Needless to say we have all the latest drivers on everything. We have
>>>spent
>>>2 days on this and got nowhere. Most frustrating is that when we tested
>>>this
>>>combination of hardware prior to the SP2 rollout it worked fine. In fact
>>>we
>>>have 2 of the 62 machines in the combinations that *CAN* connect to the
>>>WLAN
>>>after Sp2....which is even more frustrating......and if we re-image a
>>>machine that cant connect down to SP1...it immediately connects to the
>>>WLAN.
>>>
>>>So it seems that SP2 plus specific WLAN hardware combinations is
>>>unpredicatable. Can anyone give any times as to where we can even start
>>>to
>>>trouble shoot this issue.
>>>Regards
>>>Al Blake, Canberra, Australia
>>>
>>
>
>