Domain Naming System Information
This page has been set up for the user community of the School of Computer Science to verify their individual computer's Domain Naming System (DNS) setup.
Instructions on how to verify DNS settings on a Windows XP machine
The following steps show how to check the DNS settings of individual Windows XP machines to verify DNS settings.
Verify current DNS settings by doing the following:
- Click the Start button
- Choose the Run command
- In the Run window type cmd
- Click the OK button
- In the command prompt window type the following command ipconfig /all
- Verify the current DNS Servers by looking at the descriptor named DNS Servers. There could be several name servers listed.
To change the DNS settings on your Windows XP machine do the following:
Click the Start button
- Select *Settings -> Control Panel*
- In the Control Panel Window double click on Network Connections
- In the Network Connection Window double click on the Local Area Connection. If you have more than 1 choose the connection with no number after it i.e. Local Area Connection
- In the Local Area Connection Status Window click on the Properties button
- In the Local Area Connetion Properties window under the General tab double click on Internet Prototol (TCP/IP)
If the Radio button that reads Obtain DNS server address automatically is active you should have no problem.
If the radio button that reads Use the following DNS server addresses is active you will need to verify the listed preferred and Alternate DNS servers.
To add the DNS servers do the following in the Internet Protocol (TCP/IP) Protocol window
- In the bottom of the General tab click on the Advanced button
- In the Advanced TCP/IP Settings Window click on the DNS tab
- Click on the Add button under the box titled DNS server addresses, in order of use:
- Add the following IP addresses from the list below
- When you have added the DNS sever IP addresses click OK in the Advanced TCP/IP Settings Window
- Click OK in the Internet Protocol (TCP/IP) Protocol window
- Click OK in the Local Area Connection Properties Window
- Close the Local Area Connetion Status Window.
- If your machine requests that you reboot it for the changes to take affect please reboot it.
Instructions on how to verify DNS settings on a Linux or Macintosh machine
Instructions on how to update the DNS servers on a Linux machine
- Login in to the machine and bring up a terminal window
- To change the name server information you must edit the /etc/resolv.conf file
- In terminal window edit the /etc/resolv.conf file using your favorite editor, see the list below of the current DNS servers
- Save the file and exit
Instructions on how to update the DNS servers on a Macintosh machine
- Login in to the machine and bring up Preferences
- Choose Internet and Network
- Click on Network
- Click on the TCP/IP button and look at the configure IPv4 section
- If the adapter is set to manual verify the listed names in the box against the servers from the list below
- If you are running DHCP you do not have to make any changes
Active SCS DNS servers
DNS Server Name IP Address AC-CDNS-1.NET.CS.CMU.EDU 18.104.22.168 AC-CDNS-2.NET.CS.CMU.EDU 22.214.171.124 AC-CDNS-3.NET.CS.CMU.EDU 126.96.36.199