On 3/28/2014 6:58 PM, Curtis, Bruce wrote:
We have seen a small number of similar problems but in some cases they may
have been Intel wireless chips that did not get DHCP when other clients were
also connected to an AP.
http://www.intel.com/support/wireless/wlan/sb/CS-034535.htm
A work around that some folks here found (not sure if it works for both
Intel and Broadcom) was to disable 802.11n on the problem machines so they just
used the older 802.11 speeds. Once 802.11n was disabled on the problem
machines they obtained IPs via DHCP just fine. Since it was only a small
number of machines we have not discovered more details but I suspect it may be
related to our disabling of lower 802.11n speeds on our wireless network.
(Lower 802.11 speeds are also disabled).
Bruce, I believe this particular issue is an Intel driver bug --
disabling N support apparently avoids the buggy code, so your network's
disabled lower 802.11n speeds may not be relevant. (I'm afraid this is
just "stuff I've seen online when exploring Win 8.1 wifi issues" thus I
don't have a reference.)
We are having Win8.1 Broadcom and Intel issues on a Meraki network, so
it is not only Cisco gear that triggers these issues.
I've also seen it suggested online that the bug-fixed versions of the
Intel drivers had not be certified or whatever for Win8.1, thus some
users hit this issue when the 8.1 upgrade forced their systems back to a
buggy version of the driver.
Broadcom Win 8.1 problems also sometimes seem to be helped by going to a
Win7 driver (when available) but it is not clear to me if this is a
driver bug by Broadcom, or if Win8.1 has changed driver requirements in
a way that breaks WPA2-Enterprise.
Still no real evidence of "root causes" for Win8.1 wifi flakiness on
Enterprise networks. One of our affected users has a new Surface Pro
something tablet with Broadcom wifi, and I was hopeful that if he
pursued it with MS support we might find if the issue was the drivers or
the OS, but so far he's not really gotten anywhere.
One thing I find a bit frustrating is users who are sure that the issue
is our network rather than their laptop, because their laptop works fine
on all the WPA2-Personal networks they try. As far as I can tell, a
device's wifi stack can be fine for WPA2-Personal yet totally hosed for
WPA2-Enterprise.
Steve Bohrer
ITS, Bard College at Simon's Rock
413-528-7645
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