Carnegie Mellon University School of Computer Science

How to check DNS settings

Off-campus computers or routers that have been specifically configured to use SCS caching name servers will no longer be able to perform DNS lookups when not located on the Carnegie Mellon network.

Use the instructions below for the appropriate operating system to confirm whether you will be impacted by this change.

The SCS caching nameserver IP addresses to look for start with 128.2.

Please follow the instructions for the appropriate operating system below. You can also submit a ticket for assistance. 

  1. Open the Control Panel by clicking on the Windows button, then click Control Panel
  2. Type "Network and Sharing" in the upper right hand corner and click on Network and Sharing Center
  3. Click Change Adapter Settings
  4. Right click on the network adapter you'd like to check (wired or wireless) and click Properties
  5. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties
  6. Make sure you do not have the SCS DNS entries listed under Use the following DNS server addresses
  7. Instead, select Obtain DNS server address automatically
  1. Open System Preferences, either from the Dock or the Apple menu > System Preferences
  2. Click Show All
  3. Click Network

    Note: If the lock in the lower-left corner of the window is closed, you must click it and enter your Mac OS X administrator password before you can make changes to settings.

  4. In the left-hand pane, choose the network connection you want to check
  5. Select the Advanced button and the DNS tab
  6. If you have manually entered settings, the SCS DNS servers will be listed in black font. If this is the case, use the minus ( - ) button to remove them If you're on campus and the DNS servers appear in gray font, that means they are automatically assigned. When you leave the Carnegie Mellon campus, your DNS settings will be updated to your local network provider and you will not be affected by the DNS update.
  1. Select the Network icon in the top panel
  2. Select Edit Connections
  3. Choose the network connection you want to check
  4. Click Edit
  5. Select the IPv4 Settings tab
  6. Make sure you do not have the SCS DNS entries listed under DNS servers
  7. Instead, set the Method to Automatic (DHCP) and click Save
  1. Right-click the Network icon in the top panel 
  2. Select Edit Connections
  3. Choose the network connection you want to check
  4. Click Edit
  5. Select the IPv4 Settings tab
  6. Make sure you do not have the SCS DNS entries listed under DNS servers
  7. Instead, set the Method to Automatic (DHCP) and click Save