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Original poster
Apr 12, 2001
55,040
17,421



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Princeton University has detailed wireless issues with Apple's iPad that have resulted in the university blocking several of the devices from its wireless network. While frequently invisible to end users and apparently unrelated to most early complaints from iPad owners about Wi-Fi connectivity issues, the iPad issue documented by Princeton can result in interference of network usage by other devices.

Princeton reports that they have seen a number of iPads with errors in their Dynamic Host Configuration Protocol (DHCP) protocol.
The malfunction we see is that the iPad uses DHCP to obtain a lease, renews the lease zero or more times (as expected), but then continues using the IP address without renewing the lease further. The iPad allows the DHCP lease to expire, but it continues using the IP address after allowing the lease to expire. The incident continues for some time (typically hours); usually it ends when the iPad asks for a new DHCP lease, or the iPad disconnects from the network.
Essentially, the iPad is continuing to use IP addresses that have already been reclaimed by the university's routers. Similar problems could explain certain issues that users have been seeing in their own personal use of the device, although user complaints regarding Wi-Fi performance have primarily focused on poor signal strength and inconsistent connections.

As of April 19th, 25 of the 41 iPads on the campus network had shown this issue while 9 have been blocked due to repeated problems. Princeton is reportedly working with Apple to address this issue, but has developed a tentative workaround to assist with the problems. Some of the nine blocked iPads have since been unblocked after the owners performed the suggested workaround. Princeton's current policy with respect to iPads is to allow them onto their network, and in the case of DHCP lease issues, notify the user and point them to the workaround. Only if problems continue after that point would a specific device be blocked.

Article Link: Princeton University Details iPad Wireless Networking Issues
 

callaghan001

macrumors newbie
Dec 27, 2006
14
0
London, UK
Basic stuff?

Surely this should be basic stuff to get right?

If ( [Lease isExpired] )
[device requestLease];
else
.......

Or something like that, it should be fixable in an update hopefully. I wonder what the workaround is though?
 

PAC88

macrumors 6502
Apr 23, 2009
457
0
Apple should probably look into the wireless issues related to the Macbook Pro's also..
 

jo0

macrumors regular
Nov 25, 2009
224
0
Seattle, WA
no mate...far to simple. they have bookshelves on the ipad to update now. thats hardcore.


Surely this should be basic stuff to get right?

If ( [Lease isExpired] )
[device requestLease];
else
.......

Or something like that, it should be fixable in an update hopefully. I wonder what the workaround is though?
 

alent1234

macrumors 603
Jun 19, 2009
5,688
170
i'm shocked Apple QA didn't see this in their super secret locked down lab with only one person authorized to touch the iPad
 

mikethebigo

macrumors 68020
May 25, 2009
2,169
663
Interesting read. Should be easy to fix.

It's worth noting that this isn't the reason that George Washington University doesn't support iPads, despite everything the media is saying about them being "banned." The truth is GW uses a SSL VPN client for wireless security, which the OS does not yet support (it's coming with 4.0).
 

Winni

macrumors 68040
Oct 15, 2008
3,207
1,195
Germany.
Apple's QA completely sucks. They're a company that wants everything to be wireless, and their devices don't even perform properly on a basic level.
 

powderblue17

macrumors regular
Mar 16, 2007
175
0
Well the last time something like this came up with iPhones at Duke the blame was put on Apple when it was later discovered to be an issue with the Cisco equipment. If it really is the iPad then why is it an isolated case?
 

callaghan001

macrumors newbie
Dec 27, 2006
14
0
London, UK
no mate...far to simple. they have bookshelves on the ipad to update now. thats hardcore.

:eek: Your right!! I completely forgot!! it should be

if ( [lease isExpired] && [SteveJobs saysYes] && [iPhone4g isSecret])
[device requestLease];
else
[iPhone4G createLeak];
:p lol
 

Zoboomafoo

macrumors 6502
May 22, 2002
420
705
Until I hear this is a rampant problem on universities (and with wifi in general), i have to wonder if this is Apple's problem, or Princeton's.
 

kernkraft

macrumors 68020
Jun 25, 2009
2,456
1
Well, involving universities and proper real-life experts to fix Apple's mistakes should have been done in the development stage. The next time some Apple employee goes to a bar, he/she should hook up with some students too.
 

devinher

macrumors member
Mar 5, 2010
32
1
Will this work for students?

I'm really curious to see how students use the ipad. To me, it sounded like a dream machine for solving my lifelong pain around note taking. Finally, I would be able to take notes, without being rude (clack, clack, clack with a screen between my and others) and not only be able to read them later, but search them.

Sadly, when I tried typing on the ipad at an Apple Store, I found it extremely difficult. I know people will improve with practice, but is it realistic to think that a student could write a paper on an ipad or a business user could write a substantive memo?
 

kungming2

macrumors regular
May 31, 2007
124
0
Speaking as a student currently enrolled at Princeton, I do want to note that Princeton is immensely anal/aware of networking snafus - they are often quite willing to block students who may have accidentally messed the network up somehow. For example, any iPhones or iPods with Apple's Remote app are banned from the network.
 

callaghan001

macrumors newbie
Dec 27, 2006
14
0
London, UK
Re: Apple remote app

Speaking as a student currently enrolled at Princeton, I do want to note that Princeton is immensely anal/aware of networking snafus - they are often quite willing to block students who may have accidentally messed the network up somehow. For example, any iPhones or iPods with Apple's Remote app are banned from the network.

Are you referring to the remote for iTunes?

Thats a bit harsh, surely that would be just small traffic being passed internally, most networks can cope with this quite well.

Or is it the noise it creates (popping up in peoples iTunes etc) causing the problem?
 

mikethebigo

macrumors 68020
May 25, 2009
2,169
663
I'm really curious to see how students use the ipad. To me, it sounded like a dream machine for solving my lifelong pain around note taking. Finally, I would be able to take notes, without being rude (clack, clack, clack with a screen between my and others) and not only be able to read them later, but search them.

Sadly, when I tried typing on the ipad at an Apple Store, I found it extremely difficult. I know people will improve with practice, but is it realistic to think that a student could write a paper on an ipad or a business user could write a substantive memo?

For long document creation, you'll wish you had a physical keyboard, trust me.
 

ghostface147

macrumors 68040
May 28, 2008
3,657
3,953
Last week as all good for Apple as far as product releases and annoucements, but this is a terrible leak showing how bad their QA was with the iPad's wireless issues and of course iGate.
 

kungming2

macrumors regular
May 31, 2007
124
0
Are you referring to the remote for iTunes?

Thats a bit harsh, surely that would be just small traffic being passed internally, most networks can cope with this quite well.

Or is it the noise it creates (popping up in peoples iTunes etc) causing the problem?

Yeah, the same app. The sheer number of shared libraries and iTunes stuff broadcasting over a single node of the network (in the library, you get maybe 20-30 in your source list sometimes) is apparently the reason for blocking it. If you bring in your iPod to diagnose problems at the tech place, they'll make you delete the app if you have it on there.
 

walnuts

macrumors 6502a
Nov 8, 2007
539
173
Brooklyn, NY
I'm no wireless expert, but I found OIT to be really draconian with their network. I ran into several problems with them with my iPhone, trying to use a time capsule, and setting up wireless access for a Wii. I really don't know enough to be sure, but I am at least suspicious as to whether these iPads are really causing problems vs. just not behaving "properly".
 

hackersword

macrumors newbie
Mar 6, 2008
2
0
Do any of you actually read the entire article?

http://www.net.princeton.edu/announ...-lease-keeps-using-IP-address.html#othersites
Why Haven't Other Sites Reported This Particular Issue?

When we first described the problem, some asked why only Princeton was seeing a problem. Understandably, some suggested that because other sites were not reporting it, the problem must be due to a problem with Princeton's network. ....
I won't cut/paste the entire thing, but for those of you who are questioning, "well why is it just Princeton, maybe its their network", I advise you to actually read the section where they actually address that EXACT question in length.

tl;dr - As other guy said, Princeton is insanely anal about Networking monitoring and go far above what is industry standard
 
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