Windows 7 Thinkpad with intermittent wireless only in the residences

[An Nguyen (Munger Zone S RCC)]

Hi all,
I've got a resident who was having problems with his wireless connection
with Vista. He then upgraded (not a clean install) to Windows 7. His
wireless now works in the law school but not in Munger. In Munger, he can
consistently connect to Stanford Residences and gets the right IP, DHCP and
DNS. Intermittently (more often than not), the connection will slow down to
the point pages partially load or not at all. The interesting part is that
he rarely shows up at all on the DHCP logs. At one point this month, no
activity on the logs (discover, offer,request, ack or nack) was shown for
over a week even though he is on the network. We already checked the usual
Vista culprits of IPv6 and the DHCP broadcast flag along with reinstalling
the wireless adapter, updating the driver, resetting winsock, and trying in
safemode. I'm running out of ideas. Any thoughts?

Thanks,
An

An M. Nguyen
Stanford University
Mechanical Engineering, Medicine Graduate Student
Grad RCC: Munger Zone S - 1, 3, Cluster
CA: Munger 1

e: ***@stanford.edu
p: [phone]
w: http://www.anmnguyen.com

[An Nguyen (RCA)]

Hi all,
The resident had a b/g/n wireless card. Gene suggested turning off N mode
(done through the driver configuration). Since the resident has been
unresponsive, I'm assuming that it worked. So this is worth a shot if your
resident is having issues. There are residents who have it enabled and are
not having any problems in the residences or on campus.

As for the DHCP log strangeness, it's likely due to the older log collection
method. The laptop wasn't having any issue being assigned an IP address.

An

An M. Nguyen
Stanford University
Mechanical Engineering, Medicine Graduate Student
Grad RCC: Munger Zone S - 1, 3, Cluster
CA: Munger 1

e: ***@stanford.edu
p: [phone]
w: http://www.anmnguyen.com


On Wed, Nov 18, 2009 at 22:50, Diana Gentry (EV Zone K RCC) <

Try an ipconfig /release and ipconfig /renew on that interface, then enter
the IP address that he gets into the DHCP log tool (not his hardware
address, the IP address you see him get). If the hardware address
corresponding to that interface isn't in the results for that IP address, or
it is but doesn't show that recent request/ack, then I think you'll have to
file a HelpSU ticket on that alone. (It's not unusual for there to be days
or weeks without a discover/offer if he's not moving networks often, but
there should definitely be requests/acks no more than a few days old).
I'd also try checking the signal strength with a tool like iStumbler or
KisMAC, checking data throughput with netspeed.stanford.edu during a
"slow" period (which may tell you if you're getting unusual packet loss, for
instance), and (if you're feeling adventurous) doing frame and packet
captures with WireShark. That's not targeting any specific cause, just
looking to gather more information.
Hope that's helpful,
Diana

Post by An Nguyen (Munger Zone S RCC)
Hi all,
I've got a resident who was having problems with his wireless connection
with Vista. He then upgraded (not a clean install) to Windows 7. His
wireless now works in the law school but not in Munger. In Munger, he can
consistently connect to Stanford Residences and gets the right IP, DHCP and
DNS. Intermittently (more often than not), the connection will slow down to
the point pages partially load or not at all. The interesting part is that
he rarely shows up at all on the DHCP logs. At one point this month, no
activity on the logs (discover, offer,request, ack or nack) was shown for
over a week even though he is on the network. We already checked the usual
Vista culprits of IPv6 and the DHCP broadcast flag along with reinstalling
the wireless adapter, updating the driver, resetting winsock, and trying in
safemode. I'm running out of ideas. Any thoughts?
Thanks,
An
An M. Nguyen
Stanford University
Mechanical Engineering, Medicine Graduate Student
Grad RCC: Munger Zone S - 1, 3, Cluster
CA: Munger 1
p: [phone]
w: http://www.anmnguyen.com

[Ethan Y Rikleen]

Izaak,

Please report this problem to ***@rescomp. Include as
many details for affected people as possible: wireless hardware
address, IP address obtained, signal strength, time of the incident,
location in the dorm. Hardware address is most important as then
perhaps they can track the association history.

FYI the DHCP logs site is
http://dhcplog.stanford.edu:9696/manage/dhcplog/check_db
It's also linked from the RCC manual and the SUNet Reports page.

-Ethan

Date: December 9, 2009 5:21:20 PM PST
Subject: Re: Windows 7 Thinkpad with intermittent wireless only in
the residences
Hi all,
WestFlo is having a widespread, similar problem. Since coming back from
Thanksgiving, we've had a handful of people complaining that their wireless
ducks out like An described, with the signal weakening to the point of
disconnection, followed by a strong-signal reconnect and repeat. This has
only happened to residents in Mirlo and Paloma, while they're in the dorm -
when elsewhere they've had no problems. While Gavilan and Loro are on the
same wireless subnet, we've yet to receive any complaints from either dorm.
The information received with the connection is consistently right (right
IP, right DNS servers, right DHCP server); moreover, the problem seems to be
isolated to certain time periods, during which it affects everyone involved.
Those time periods don't always coincide with peak-usage though: we'll have
a few full days of the problem, followed by a few days of perfect wireless,
etc.
I've tried An's later suggestion of turning of 802.11n. However, the
wireless card in every instance of this that I've come across doesn't
support 802.11n. As far as I can tell, they're all older laptops (2-3 years
old), both Mac and PC. I've also tried looking for the DHCP logs, but as
per Shannon's post earlier, that site seems to be down. Am I looking in the
right place? dhcplog.stanford.edu:9696?
My first reaction after gathering this info is that something may have
happened with the routers in Mirlo and Paloma during Thanksgiving break.
Does anyone know how I could find out if this is true, and if so, find out
what changed? I've filed a HelpSU request, however I haven't gotten any
useful info back - someone said they'd come out and look at it, but as far
as I know that never happened.
Is anyone else experiencing this issue, or something similar? Any ideas
much appreciated.
Thanks, and good luck with finals!
-Izaak (and James)
WestFlo RCCs
"Diana Gentry (EV Zone K RCC)"
wrote in
message

Try an ipconfig /release and ipconfig /renew on that interface, then enter
the IP address that he gets into the DHCP log tool (not his hardware
address, the IP address you see him get). If the hardware address
corresponding to that interface isn't in the results for that IP address,
or it is but doesn't show that recent request/ack, then I think you'll
have to file a HelpSU ticket on that alone. (It's not unusual for there
to be days or weeks without a discover/offer if he's not moving networks
often, but there should definitely be requests/acks no more than a few
days old).
I'd also try checking the signal strength with a tool like iStumbler or
KisMAC, checking data throughput with netspeed.stanford.edu during a
"slow" period (which may tell you if you're getting unusual packet loss,
for instance), and (if you're feeling adventurous) doing frame and packet
captures with WireShark. That's not targeting any specific cause, just
looking to gather more information.
Hope that's helpful,
Diana

Post by An Nguyen (Munger Zone S RCC)
Hi all,
I've got a resident who was having problems with his wireless connection
with Vista. He then upgraded (not a clean install) to Windows 7. His
wireless now works in the law school but not in Munger. In Munger, he can
consistently connect to Stanford Residences and gets the right IP, DHCP
and
DNS. Intermittently (more often than not), the connection will slow down
to
the point pages partially load or not at all. The interesting part is
that
he rarely shows up at all on the DHCP logs. At one point this month, no
activity on the logs (discover, offer,request, ack or nack) was shown for
over a week even though he is on the network. We already checked the
usual
Vista culprits of IPv6 and the DHCP broadcast flag along with
reinstalling
the wireless adapter, updating the driver, resetting winsock, and trying
in
safemode. I'm running out of ideas. Any thoughts?
Thanks,
An
An M. Nguyen
Stanford University
Mechanical Engineering, Medicine Graduate Student
Grad RCC: Munger Zone S - 1, 3, Cluster
CA: Munger 1
p: [phone]
w: <http://www.anmnguyen.com>http://www.anmnguyen.com

Jennifer Ly
Senior Consulting Manager
Student Computing
Stanford University