Software-based iPad Wi-Fi problems detailed by Princeton

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Comments

  • Reply 21 of 50
    mstonemstone Posts: 11,510member
    Quote:
    Originally Posted by MJ Web View Post


    Requires simple software fix.



    Yep. Not that big of a deal. They probably use a really short lease like an hour. I set mine to 7 days on the server. The iPad is using the network even though the screen is locked to listen for IM and other background WIFI functions. But if there is an IP address shortage at Princeton that might explain a short lease.



    Apple needs to fix it but for most people other than Princeton or other really crowded networks it would be a non-issue.
  • Reply 22 of 50
    mrodmrod Posts: 6member
    It sounds as if a programmer used
    if (leaseend == current_time)
    rather than
    if (leaseend <= current_time)
    Oops!
  • Reply 23 of 50
    djdjdjdj Posts: 74member
    I haven't had this problem with my iPad, but my Mac does something similar. When it wakes from sleep it often assumes it can continue using the same IP address it had when it went to sleep. When it discovers another device is using that address it pops up an error on screen and I have to manually re-obtain an address, rather than obtaining a new address on its own. It's very irritating.
  • Reply 24 of 50
    mstonemstone Posts: 11,510member
    Quote:
    Originally Posted by Naboozle View Post


    The device has responsibility NOT use an dynamic address without an active and valid lease. Duplicate IP addresses can be a nasty problem.



    I think it is definitely a problem not sure how nasty, one or both devices should receive the error "The IP address 192.168.1.XXX is being used by another client on the network". Then you have to close the network and relaunch. I wonder if Princeton is IPV6?
  • Reply 25 of 50
    Quote:
    Originally Posted by PaulMJohnson View Post


    Amazing how quick AI readers are to suggest Princeton are in the wrong here. This is clearly a bug in the iPad software, and I would guess Apple will be happy with the methodical way Princeton have isolated the bug so they will be able to re-create it and fix it easily.



    The company I work for locks down it's network to this sort of level also. Networks within companies are pretty much mission critical, and anything that misbehaves is treated as a potential threat.



    People here need to remember that just because we like Apple products does not mean Apple are infallable.



    You are clearly a paid M$ shill. Apple rulz, lololol. Expect to begin receiving hate mail for suggesting that Apple is anything less than perfect.
  • Reply 26 of 50
    al_bundyal_bundy Posts: 1,525member
    Quote:
    Originally Posted by charlituna View Post


    I think I have found 5 schools that are anti-ipad. and actually none of them have banned it. just they won't be giving them away to students. And 4 of them admitted that their campus networks can't handle the potential added load which is why they won't give them away or carry them in the campus store at this time.







    wouldn't keeping track of assigned IPs and not duplicating assignments be a part of the network not the device software.





    that's not how DHCP works. the client is responsible for not using an IP after the lease expires.



    and in this case the iPad is keeping an address that it's not supposed to have. what happens then is that when the wifi router asks which machine has so and so IP, two devices answer. on copper it's called an ARP request or something like that
  • Reply 27 of 50
    Quote:
    Originally Posted by aaarrrgggh View Post


    The problem comes as the devices get more popular. Not giving up a DHCP lease is a big deal, but I understand why it would be done (especially on networks with ridiculously short lease periods) to conserve battery life.



    I think we are coming into the dawn of the era where WiFi just stops working effectively. A single access point can't support that many users-- 50-60 on the good equipment, 20-25 on the cheap stuff. It really requires a lot more effort than it did 3-5 years ago to make things work effectively.



    If your access point is doing the DHCP (bad design), your network will come to its knees quickly. If you centralize management of the access points and have reasonable address space for the DHCP it shouldn't be a major issue though.



    I'm not sure that I agree (that this is a big deal). On our network, all that would happen is the second user who was given an IP that is still in use by a sleeping iPad somewhere, would get a conflict dialogue and then immediately get a new IP. It's not like it's a static IP. Other than the transient dialogue box (on a tiny amount of computers a tiny amount of the time), there would be no real disruption to service.



    Princeton admits in their statement to having a network where they monitor these things rather more closely than is typical in the industry. I'm thinking the other institutions didn't discover it because of the fact that Princeton is the only one doing the deep IP analysis and therefore the only one noticing it.



    What I dislike, is Princeton making this big announcement, and screwing over their users at the same time as they are disparaging the iPad when it all just seems unnecessary.
  • Reply 28 of 50
    Quote:
    Originally Posted by nasdarq View Post


    Sure, it's not Apple's fault There are a number of universities that have already banned it. AI should just probably google for more articles, they are all over the web.



    In those articles, the bans are about the wireless networks simply being overwhelmed by the amount of data the influx of new devices has demanded.

    This particular problem - the release of IP addresses - is new as far as I can find.



    Maybe, if you had some technical understanding of the difference between the two problems, you'd be less snide?
  • Reply 29 of 50
    bartfatbartfat Posts: 434member
    What I don't understand is how the iPhone is not susceptible to these same failures, because aren't they based off the same chipset for wireless? So the code for the iPad and iPhone should be the same, right? I'm guessing the 3GS would have these problems too...? Because they're using essentially the same OS and same hardware.
  • Reply 30 of 50
    Quote:
    Originally Posted by Prof. Peabody View Post


    I'm not sure that I agree (that this is a big deal). On our network, all that would happen is the second user who was given an IP that is still in use by a sleeping iPad somewhere, would get a conflict dialogue and then immediately get a new IP. It's not like it's a static IP. Other than the transient dialogue box (on a tiny amount of computers a tiny amount of the time), there would be no real disruption to service.



    Princeton admits in their statement to having a network where they monitor these things rather more closely than is typical in the industry. I'm thinking the other institutions didn't discover it because of the fact that Princeton is the only one doing the deep IP analysis and therefore the only one noticing it.



    What I dislike, is Princeton making this big announcement, and screwing over their users at the same time as they are disparaging the iPad when it all just seems unnecessary.



    How do you expect them to get headlines? This is a non-story but Princeton needs a bit of the old spotlight. This will pass. Apple will fix the wifi drivers and la de da.
  • Reply 31 of 50
    soskoksoskok Posts: 107member
    Quote:
    Originally Posted by solipsism View Post


    You changed your MAC address, didn't you?



    College years used to get banned every bloody day...
  • Reply 32 of 50
    mstonemstone Posts: 11,510member
    Quote:
    Originally Posted by bartfat View Post


    What I don't understand is how the iPhone is not susceptible to these same failures, because aren't they based off the same chipset for wireless? So the code for the iPad and iPhone should be the same, right? I'm guessing the 3GS would have these problems too...? Because they're using essentially the same OS and same hardware.



    Actually iPhone is 3.1.3 and iPad is 3.2. iPhone OS 3.2 probably is closer to iPhone 4.0 beta which I believe has had a few WIFI bugs reported so far.
  • Reply 33 of 50
    dr millmossdr millmoss Posts: 5,403member
    Quote:
    Originally Posted by WilliamG View Post


    Princeton.



    GWU



    Cornell.



    None of them lightweights. My guess is that textbook publishers are taking notice of this trend.



    False. Princeton says definitively that they have not banned the iPad. GWU have blocked all iPhones and iPads from joining their wireless networks because of specific issues with their networks which they are working on correcting. Likewise you are wrong about Cornell. The iPad is not blocked from their networks at all. None of these campuses have "banned" the iPad.
  • Reply 34 of 50
    The wifi problem with the iPad reminds me of this



    http://www.dukenews.duke.edu/2007/07/cisco_apple.html
  • Reply 35 of 50
    Quote:
    Originally Posted by WilliamG View Post


    I have heard that an increasing number of universities and hospitals are banning the iPad for various reasons.



    I hope that Apple or someone else can fix that.



    Without university support, the dream of textbooks widely issued on the iPad becomes more distant.



    And medical use? That too was thought to be a promising market.





    You and your use of the passive voice are wrong



    http://www.cit.cornell.edu/news/stor...ID_1942=162201
  • Reply 36 of 50
    davegeedavegee Posts: 2,765member
    Quote:
    Originally Posted by djdj View Post


    I haven't had this problem with my iPad, but my Mac does something similar. When it wakes from sleep it often assumes it can continue using the same IP address it had when it went to sleep. When it discovers another device is using that address it pops up an error on screen and I have to manually re-obtain an address, rather than obtaining a new address on its own. It's very irritating.





    Okay, I know this 'issue' is NOT the first time I've heard about this... Why do I remember this exact? similar? problem happening to Mac laptops with airport cards...



    Maybe I'm wrong, but this type of problem sounds _very_ familiar however it was QUITE some time back... perhaps in the very early days of Apple Airports becoming mainstream. This issues I'm reminded of might go back to 1999, 2000, 2001... Tried searching google but searching out 'ancient problems' isn't so easy.



    Oh and to those who try and suggest that the iPod isn't looked kindly on at college campuses... might wanna read this.



    Quote:

    "Seton Hill University recently promised free iPads for every student arriving in the fall, as part of the school's technology program. The devices will be used for reading digital textbooks, communication, file sharing, note taking, and other tasks."



    and other tasks... *cough* CRAZY-NET-PORN *cough*



    Apologies for the childish comment but it was screaming at me, so I had to do it....
  • Reply 37 of 50
    cam'roncam'ron Posts: 503member
    Quote:
    Originally Posted by al_bundy View Post


    except when it wakes up and still has the same IP it will cause a conflict with another device that was assigned that IP



    Ah, I was under the impression that it was in an on state. I guess I misunderstood. Makes more sense now. Thank you.
  • Reply 38 of 50
    Quote:
    Originally Posted by walshbj View Post


    You have to wonder why there aren't tons of universities reporting similar problems.





    The issue is specifically noticable there because Princeton's own docs on the problem say they use a very short lease interval because Princeton wants their client IP addresses to be reachable globally and not hidden behind NAT (address translation)



    Those are in short supply and that's what's driving the three hour lease cycle.



    Maybe a Mod can merge my thread here. Has link to Princeton's docs

    Paul



    http://forums.appleinsider.com/showthread.php?t=108860
  • Reply 39 of 50
    Quote:
    Originally Posted by WilliamG View Post


    Princeton.



    GWU



    Cornell.



    None of them lightweights. My guess is that textbook publishers are taking notice of this trend.



    Nonsense.



    Textbook publishers would be stupid to base long-term decisions based on short-term hiccups like these which will disappear in weeks. I recall people complaining about the same thing when the iPhone originally came out.
  • Reply 40 of 50
    Quote:
    Originally Posted by der passant View Post


    The wifi problem with the iPad reminds me of this



    http://www.dukenews.duke.edu/2007/07/cisco_apple.html



    There you go. Thanks. That's the similarly silly story from the past that I recalled!
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