iPad WiFi works only with WPA/TKIP, not WPA2/AES

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iPad WiFi works only with WPA/TKIP, not WPA2/AES

My iPad (like so many others) stopped connecting to my Linksys WRT54G router (which like everyone else's connects fine with every other device, including non-iOS 4 iPhones). The whole reset/restart/restore dance with the iPad/router/cable modem was performed to no avail. By sheer desperation, security protocols were changed, and that's what finally worked.

The protocol to the rescue was WPA/TKIP, curiously enough. (When security is completely disabled ("Open"), the iPad also connects, perhaps expectedly.) The culprit is WPA2/AES (even AES+TKIP). Any iteration of WPA2/AES ends up blocking the iPad from getting the appropriate IP address via DHCP. Once I changed to WPA/TKIP, everything's been rock-solid and fast.

(The only times WPA2/AES worked was when the iPad was first used for a couple days, and a couple days after switching back to WPA2/AES when it started working with WPA/TKIP. Since then, switching back to WPA2/AES no longer works, even temporarily.)

Any idea why initially WPA2/AES worked, and then suddenly stopped?

iPad 64GB 3G, iOS 4, iPhone (iOS 3.1.2), iMac SE (OS X 10.4)

Posted on Jan 12, 2011 2:57 AM

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Answer 1

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JimHdk

Level 7

28,874 points

Jan 12, 2011 3:55 AM in response to TashTish

I use WPA2/AES with 4.2.1 all the time with my iPad and router (Netgear WGR614v10) with no problems so there isn't something inherently wrong with the iPad and WPA2.

The Linksys WRT54G router is quite venerable and has been around for 9 years or so going through 12 versions. The latest is 8.2 I believe. When you say that you are using a WRT54G it doesn't really pinpoint exactly what you have. One would have to know the version and the firmware level as well. Whatever version you have make sure that it has the latest firmware for the version (see http://homesupport.cisco.com/en-us/wireless/lbc/WRT54G/download).

You could have a hardware problem with your iPad. The only way to tell would be to tet it on some other networks using WPA2 or give it to Apple for some testing.

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Answer 2

Jan 12, 2011 3:56 AM in response to TashTish

That is a very interesting question, and one there probably will not be a satisfacory answer for. It probably involves the combination of the router and the iPad and their respective implementations of the AES encryption algorithm. The AES algorithm is considerably more complex than TKIP. Why some have problems and not others has to be related to the router and its implementation and the Apple implementation. I say that because it works fine for me connecting with a Verizon FiOS (Actiontec) router. And I can connect seemlessly with an AirPort Extreme. But there have been a number of posts recently about problems with Linksys and Belkin connectivity.

Bottom line is there is probably not an easy solution...and since you do have a strong security protocol that works, keep using it. Very strange that there would be a change in connectivity after a few months, though.

Old engineering philosophy, if it ain't broke, don't fix it. If you have something that works, stick with it for now.

But also give feedback to Apple:

http://www.apple.com/feedback/ipad.html

Ralph

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Answer 3

Jan 12, 2011 4:01 AM in response to TashTish

Jim's comment about firmware is especially important...forgot to address that myself. Just this week I decided to update the firmware on my router (something kept telling others to do on here for months) and it actually help speed things up with the iPad...or seems to have had that affect.

So, be sure and check for router firmware updates as soon as you can.

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Answer 4

TashTish Author

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35 points

Jan 12, 2011 9:59 AM in response to JimHdk

JimHdk wrote:
I use WPA2/AES with 4.2.1 all the time with my iPad and router (Netgear WGR614v10) with no problems so there isn't something inherently wrong with the iPad and WPA2.

I'm afraid you're right. It even worked for me (albeit for a total of three to four days).

The Linksys WRT54G router is quite venerable and has been around for 9 years or so going through 12 versions. The latest is 8.2 I believe. When you say that you are using a WRT54G it doesn't really pinpoint exactly what you have. One would have to know the version and the firmware level as well. Whatever version you have make sure that it has the latest firmware for the version (see http://homesupport.cisco.com/en-us/wireless/lbc/WRT54G/download).

Yes, that was part of the reset/restart/restore dance I mentioned earlier. I have hardware version 8.0 (out of 8.2) with the latest firmware (8.08), which unfortunately didn't fix the WPA2/AES issue (although it couldn't have hurt the rather snappy connection via WPA/TKIP, about which I am certainly not complaining.)

You could have a hardware problem with your iPad. The only way to tell would be to tet it on some other networks using WPA2 or give it to Apple for some testing.

It does seem to work on public wifi (Cablevision & AT&T hotspots) as well as at Apple Stores. I wonder if the wifi there WPA2?

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Answer 5

TashTish Author

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35 points

Jan 12, 2011 12:28 PM in response to Ralph Landry1

Ralph Landry1 wrote:
That is a very interesting question ... [involving] the combination of the router and the iPad and their respective implementations of the AES encryption algorithm. The AES algorithm is considerably more complex than TKIP. Why some have problems and not others has to be related to the router and its implementation and the Apple implementation.... t works fine for me connecting with [both] a Verizon FiOS (Actiontec) router [a]nd ... an AirPort Extreme. But there have been a number of posts recently about problems with Linksys and Belkin connectivity.

Tell me about it. I'd been pulling my hair out prior to "discovering (by accident," as George Costanza would say) that WPA/TKIP fixed the problem, and seems to be working fine and fast. Now I'm just academically frustrated (better than actually frustrated) wondering why WPA2/AES is so problematic +with this particular trifecta+ (my iPad, my Linksys router, and WPA2/AES).

Bottom line is there is probably not an easy solution ... and since you do have a strong security protocol that works, keep using it. Very strange that there would be a change in connectivity after a few months, though. Old engineering philosophy, if it ain't broke, don't fix it. If you have something that works, stick with it for now.

Actually, WPA2/AES worked on two (short but notable) occasions:

a) for two days when I first unpacked the iPad, and
b) for two days when I switched back to WPA2/AES upon discovering WPA/TKIP fixed the issue.

So it wasn't two months, which makes more sense. I agree with you that I'm not touching this arrangement for now. What I did have to do was change over the other devices (PCs, Wii's, TiVo's) that didn't automatically adjust over to WPA/TKIP. (To its credit, the iPhone did that on the fly.) Going through each device hurt a little, knowing I was using a less-than-optimal protocol for just one cranky device at expense of every other one--but of course I'd rather everything play nice than be necessarily cutting edge. (It's not like I'm the Pentagon or anything here.)

But also give feedback to Apple:
http://www.apple.com/feedback/ipad.html

Done and done. And thanks for a great and reassuring explanation.

Message was edited by: TashTish

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Answer 6

Jan 12, 2011 12:33 PM in response to TashTish

You are welcome and at least you have a working and secure system at this time.

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Answer 7

TashTish Author

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35 points

Jan 12, 2011 5:40 PM in response to Ralph Landry1

Ralph Landry1 wrote:
You are welcome and at least you have a working and secure system at this time.

Well, for what it's worth, I tried to connect to a Netgear router using WPA2/AES, and the iPad refused to play nice, generating a generic IP address, et al. <sigh> Is it time yet to say it's this iPad that's the problem? However, it does connect to wifi in Apple Stores, and isn't that WPA2/AES? As Vinnie Barbarino say, I'm so confused....

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Answer 8

JimHdk

Level 7

28,874 points

Jan 12, 2011 5:52 PM in response to TashTish

The public Apple store networks usually aren't running any security.

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Answer 9

Dogcow-Moof

Level 8

36,203 points

Jan 12, 2011 9:47 PM in response to JimHdk

Also, the iPad works just fine with WPA2/AES on a variety of other routers, including Apple's own.

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Answer 10

TashTish Author

Level 1

35 points

Jan 13, 2011 12:16 AM in response to Dogcow-Moof

JimHdk wrote:
The public Apple store networks usually aren't running any security.

Of course. Silly me. :-D

William Kucharski wrote:
Also, the iPad works just fine with WPA2/AES on a variety of other routers, including Apple's own.

I was just thinking that already two different brands are acting the same way with mine. (And after it too had worked well with WPA2 albeit all too fleetingly.) I might swap it while I have the chance to at the Store, just to see if it's the routers and not this particular iPad.

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Answer 11

Jan 13, 2011 3:58 AM in response to TashTish

Just tried looking back to see which two routers you tried and had issues with, found Linksys in your original post...there have been posts on here about problems with Linksys and Belkin. Some with Netgear. In most cases those were older routers.

One of the issues with the older routers is compliance with the IEEE 802.11 standard, the protocol that defines WiFi. The latest amendment to the standard was not adopted until Sept/Oct 2009. Routers prior to that date used various draft definitions of the n-protocol. Some are closer to the adopted standard than others. Apple was a major player in that standard, and in the iDevices latest iOS (4.2.1) seems to have applied the standard very precisely. I say seems since I do not have access to the source code and can not see what they have done. That may be a part of the mis-match showing up with the older routers and why it is so important to update the router firmware. Get closer to the adopted standard.

That can also show up in the security implementation, how closely does the firmware implement the security protocol and what algorithm is used. We are talking about matching up multiple "standards" in multiple devices. That can result in headaches for users if not done right.

Hope this helps.
Ralph

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Answer 12

Jan 13, 2011 11:13 AM in response to Ralph Landry1

Mine works fine with the following

Router: Linksys WRT54G
Firmware: DD-WRT latest stable build
Encryption: WPA2/AES G-Only
Channel: Did a site survey and its the channel that no one else is using
iPad: 32GB Wifi Only
ios: 4.2.1

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Answer 13

Jan 13, 2011 11:29 AM in response to Guybrush-Threepwood

You have a couple of important things in there: latest firmware build, and a clear channel.

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Answer 14

TashTish Author

Level 1

35 points

Jan 13, 2011 2:15 PM in response to Guybrush-Threepwood

Guybrush-Threepwood wrote:
Mine works fine with the following

Router: Linksys WRT54G
Firmware: DD-WRT latest stable build
Encryption: WPA2/AES G-Only
Channel: Did a site survey and its the channel that no one else is using
iPad: 32GB Wifi Only
ios: 4.2.1

Almost identical to me, and yet WPA2/AES doesn't work across at least two different makes of routers. Then again, maybe there's something to the effect that these are older (yet very stable) routers. I'm going to the Apple Store tonight and see if they can't duplicate it with mine and other iPads.

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Answer 15

Jan 13, 2011 2:26 PM in response to TashTish

As mentioned WPA2 does work fine with the iPad for some routers - Apple's of course. I use WPA2 encryption at home on my Apple router with no problems, and with a linksys at my in-laws - sorry I don't have model/firmware version handy. Just my 2 cents.

As well, I have a couple guys at work with non-Apple routers using WPA2/AES and their ipads without any issues.

Message was edited by: Mark Shykula

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