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Support XFINITY Internet Release and Renew Your IP Address

Introduction

When you connect your computer directly to your cable modem, you’re given a unique IP (Internet Protocol) address assigned by a Dynamic Host Configuration Protocol (DHCP) server. This is essentially your address on the Internet. Your IP address doesn’t change often, but there will be times when you’ll be assigned a short-term DHCP lease and will need to release and renew your IP address before you can reconnect to the Internet.

Why Was I Assigned a Short-term DHCP?

You may have been assigned a short-term DHCP lease for a number of reasons:

  • You connected a new device, such as a computer, or a computer with a new network interface card, to the cable modem for the first time.
  • You turned on your computer for the first time in a very long time, and the DHCP server interprets it as a new connection.
  • The device connected to the cable modem isn’t configured to DHCP. You’ll need to obtain DHCP configuration instructions for your router from its manufacturer. Check out DHCP configuration instructions for all supported Windows Operating Systems.
  • We are performing maintenance on the DHCP servers or elsewhere on our network.
  • The device connected to the cable modem is not functioning properly.
A properly configured device — regardless of the length of its lease — automatically renews its DHCP lease when the current one expires. This shouldn’t cause an interruption in service.  Occasionally, you’ll have to manually release and renew your IP address. (This may happen when there’s been a power outage, you’ve moved your computer, bought a new router, or reconfigured your home network.) Find your operating system below and follow the steps as directed.

Windows 7
Windows Vista
Windows XP
Mac OS

Windows 7

 

  1. Click Start and type CMD in the search box. 
    Run window opens and cmd is typed in the Open field. Click OK.
     
  2. Type ipconfig/release and then click Enter.
    In Console Command Window, type E:InstallConsole>ipconfig/release
     
  3. Type ipconfig/renew and then click Enter.
    In Console Command Window, on the line below Connection-specific DNS suffix,  type E:InstallConsole>ipconfig/renew

     

Windows Vista

  1. Click Start and then click in the Start Search box.
  2. Type in CMD
    CMD is typed in the Start Search box
     
  3. Type ipconfig/release and then hit Enter on your keyboard. 
    In the CMD window, type C:Userscustcare>ipconfig/release and hit Enter.
     
  4. Type ipconfig/renew and then hit Enter on your keyboard.
    In the CMD window, type C:Userscustcare>ipconfig/renew and hit Enter. 

Windows XP

  1. Click the Start menu in the lower left-hand corner of the screen then click Run.
  2. In the Run window, type CMD and click OK.
  3. Type ipconfig /release then hit Enter on your keyboard. 
    Note: There is a space between ipconfig and /release
    In the CMD window, type C:Documents and Settingsyour computer name>ipconfig /release and hit Enter. Note there is a a space between ipconfig and /release.
     
  4. Type ipconfig /renew and hit Enter on your keyboard. 
    Note: There is a space between ipconfig and /renew
    In the CMD window, type C:Documents and Settingsyour computer name>ipconfig /renew and hit Enter. Note there is a a space between ipconfig and /renew. 

Mac OS

  1. Close any open Internet applications (web browsers, email, etc.).
  2. Choose System Preferences from the Apple menu.
  3. Choose Network from the View menu.
  4. Choose Active Network Ports from the Show menu.
  5. Deselect the on checkbox for the port you use to connect to the Internet (Built-in Ethernet, AirPort, etc.).
  6. Click Apply Now.
  7. Reselect the checkbox for the port.
  8. Click Apply Now.
  9. Open a Web browser and attempt to connect.

Find this article at:

http://customer.comcast.com/help-and-support/internet/releasing-and-renewing-ip-address/