Apple iOS Personal Hotspot Annoyances

This week, I ran into an annoying feature regarding the Apple iOS Personal Hotspot function of my iPhone 5s. I had to do some software testing with various WiFi clients. This worked fine, up to the moment that new devices ran into connectivity problems.

The new devices could connect, but got a message that there was no/limited Internet connectivity. Checking the IP address of the devices showed that they had an 169 address assigned.
So the iPhone wouldn't give new IP addresses to the new devices. Earlier devices that connected correctly could reconnect without a problem though.

It turned out to be a 'normal' DHCP problem. The IP address scope on the iPhone was depleted.

The iPhone has a small DHCP address pool that can give out 16 addresses (172.20.10.0-172.20.10.15). Of these 16 addresses are 3 taken by the network, broadcast (172.20.10.0 and 172.20.10.15) and iPhone itself (172.20.10.1). Leaving 13 addresses for other devices.

In normal situations, this shouldn't be a problem, but when your testing stuff, you can run into a shortage of IP addresses. Besides the shortage of addresses there is another challenge; no way of altering the DHCP lease time, or even clearing the issued IP addresses.

The lease time for the DHCP address is approximately 1 day (85536 seconds), as shown by a little network traffic capturing below.

20:53:29.544291 56:e4:3a:38:4d:64 > 00:23:6c:8d:7f:8e, ethertype IPv4 (0x0800), length 342: (tos 0x0, ttl 255, id 45806, offset 0, flags [none], proto UDP (17), length 328)
    172.20.10.1.67 > 172.20.10.2.68: BOOTP/DHCP, Reply, length 300, xid 0xfd7e0982, Flags [none]
      Your-IP 172.20.10.2
      Server-IP 172.20.10.1
      Client-Ethernet-Address 00:23:6c:8d:7f:8e
      sname "Free-Public-WiFi"
      Vendor-rfc1048 Extensions
        Magic Cookie 0x63825363
        DHCP-Message Option 53, length 1: ACK
        Server-ID Option 54, length 4: 172.20.10.1
        Lease-Time Option 51, length 4: 85536
        Subnet-Mask Option 1, length 4: 255.255.255.240
        Default-Gateway Option 3, length 4: 172.20.10.1
        Domain-Name-Server Option 6, length 4: 172.20.10.1

There is a function to reset the network settings on the iPhone, but that just clears everything regarding (wireless) network settings, but it doesn't touch the DHCP service in the iPhone. A reboot of the iPhone doesn't do the trick either. So you just have to wait till it clears automagically.

So there is room for improvement......

AirDrop Between iOS and OS X Maverick

I got my new AirDrop-capable phone today.  Not that AirDrop was the reason for getting it, but the feature itself is quite nice; being able to send files between devices. No need to use mail or other communication methods.

This evening I shot a video on my phone and I needed it on my MacBook (with OS X Maverick). Both devices are AirDrop capable, so ..... 

And there is I went wrong. After trying for about 30 minutes to get it to work I found the answer online.... Looks like that AirDrop between different OS is NOT supported by Apple. And not supported does mean that it won't work.  

OS X: Can I use AirDrop with my computer?
http://support.apple.com/kb/ht4783
iOS: Using AirDrop
http://support.apple.com/kb/HT5887 

That is one Epic Fail if you ask me.  

iPhone Stuck At Infinite Loop After iOS Update

The old iPhone 3G got stuck in an infinite restore loop after upgrading to iOS 6.1.2 this evening. As you might understand, the misses was not amused....

The infinite restore loop means that it keeps saying that it needs to be restored from within iTunes, but after doing that several times, you tend to loose faith. After trying it several times on a Windows laptop I tried it on my iMac. While it was restoring for the who knows how many times, I did some research on the Interwebs. The results were not encouraging.

I started gathering information, and some tools (like Tiny Umbrella) to break it from its infinite loop. After the restore the iPhone booted just fine. No idea what made it break its loop. Could be coincidence, could be my iMac. No idea.​

Anyway, the misses is busy restoring the data. She (or iTunes) made a backup just before the backup. So all should be back to normal in a few minutes.​

iPhone App Distressed FX For Free

Another photo app for iOS (iPhones etc.) has been added to the Apple Store. Normally, these apps cost money, but Distressed FX is free for a limited amount of time.

View fullsize

View fullsize

View fullsize

View fullsize

Distressed Dough

The app used (predefined) filters, and blurring effects to manipulate photos. Photos can be made by the in app camera function, or by selecting a photo from your library.

My iPhone 3GS and iOS 4

Apple released the latest Operating System/software/firmware for the iPhone. This new OS (iOS) adds several new features and lots of enhancements (which I wont be going into).

I upgraded my iPhone earlier this week. No problems with that. The only real hick-up I ran into was the Voicemail number. The phone had forgotten the Voicemail, MMS and Tethering settings, so I needed to add it again. Even tethering was still available on the SIM-lock free iPhone with the KPN carrier.

There's one thing that's not 'Apple' about this update. With the regular Apple operating systems there's always the experience that an upgrade to a new release (10.4 -> 10.5 -> 10.6) leaves you with a faster/snappier OS. Even if the hardware is relatively old. Don't know how they do it, but it's something that Microsoft hasn't accomplished yet since MS-DOS 3.

Anyway, the OS upgrade on the iPhone is completely different. The device is less snappy. It looks like the device goes into some sort of suspended animation and when you need to use it it takes a couple of milliseconds (it's not much, but it's noticeable) for the phone to react. After a couple of seconds it seems to be gone.

For me, the new/improved features are more important than the snappy-ness of the device, so I'll stick to the new iOS for the moment.