How do I troubleshoot personal hotspot mode failing to issue IP addresses? When I turn on the personal hotspot, I cannot get a DHCP network address on my computer. I've tried with 2 different computers and an Android phone. They can connect to the network router but not my iPhone, which won't give out an IP address.

It just says &quot;the connection is limited&quot; and I get a 169.* address on my computer.
Wireless LAN adapter Wi-Fi:

Connection-specific DNS Suffix  . :
Link-local IPv6 Address . . . . . : fe80::5c88:c538:f588:efe%4
Autoconfiguration IPv4 Address. . : 169.254.14.254
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :

When I connect via USB cable, it does not work either:

After I reset network settings (Settings &gt; General &gt; Reset &gt; Reset Network Settings), I was able to briefly get an IP address, but I was not able to ping any servers, like Google's public DNS server. I received a phone call while the hot spot was turned on, and I believe that is what allowed me to get an IP address, but I'm not sure why. Subsequent disable/enable cycles failed to get an IP address.
$ ipconfig
Windows IP Configuration
Wireless LAN adapter Wi-Fi:

   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::5c88:c538:f588:efe%4
   IPv4 Address. . . . . . . . . . . : 172.20.10.2
   Subnet Mask . . . . . . . . . . . : 255.255.255.240
   Default Gateway . . . . . . . . . : 172.20.10.1

$ ping 8.8.8.8
Pinging 8.8.8.8 with 32 bytes of data:
Request timed out.

I even tried to connect via Bluetooth, but that didn't work either.
$ ipconfig    
Windows IP Configuration
Ethernet adapter Bluetooth Network Connection:

   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::b09b:4eb7:6091:ac17%5
   Autoconfiguration IPv4 Address. . : 169.254.172.23
   Subnet Mask . . . . . . . . . . . : 255.255.0.0
   Default Gateway . . . . . . . . . :

I have an unlocked iPhone 5 with latest iOS on MetroPCS.
Reference
http://support.apple.com/kb/TS2756. I have not restored/reset the entire phone. Would rather not have to.
This one drove me nuts but I believe this will work for most of you:

Basically the APN settings for the Hotspot were missing.

If you can browse the internet on your phone and you can activate your Hotspot but you get the yellow exclamation mark on the computer's wifi or the 'Network cable unplugged" with USB tethering, try the following:


Open Settings -> Mobile Data -> Mobile Data Network
Check the APN/Username/Password settings under "Mobile Data" (most
of the time username and password - if used - are identical, if not search APN settings on your provider's homepage)
Enter the same settings under "Personal Hotspot" further down on the same settings page
Return to Settings Menu
Switch Mobile Hotspot off and on
Connect to your Hotspot -> Internet on your computer should be working now


The problem appeared for me while roaming/after changing sims, basically every time the network settings get reconfigured and the APN settings automatically change for the roaming network/new network. 

Hope it works for you too!