I found many of people suffering from internet connectivity issue for windows phone emulator 8,
they are unable to connect internet with their emulator,

Here are some steps that i propose as solution, 

  1. Go to the Hyper-V manager and delete the emulator along with all of the virtual switches
  2. Start the emulator from Visual Studio; this will recreate it with all default settings(select yes you want to configure it to connect to the internet)
  3. Shut it down
  4. Now, go back to the Hyper-V manager
  5. Delete the snapshot that was just created for the emulator. This will prevent your changes from disappearing
  6. Find the virtual switch for your second network adapter in the Network Adapter settings(under control panel)
  7. Disable TCP/IPv4 and 6. This prevents your host machine from trying to use the connection. While you're there, get the MAC(Physical) address of this adapter
  8. Find the virtual-switch for your second network adapter under the Hyper-V settings for the emulator
  9. Change the MAC type to static and paste in the MAC address of the adapter
  10. Enable MAC spoofing/ Optional
  11. Run the emulator via Visual studio.

See Also

Another important place to find a huge amount of Windows Phone related articles is the TechNet Wiki itself. The best entry point is Windows Phone Resources on the TechNet Wiki.