Enter DNS and search domain settings on Mac
Domain Name System (DNS) servers map domain names to Internet Protocol (IP) addresses. When used in conjunction with search domains, they allow you to go quickly to websites and servers you visit frequently without typing the complete address.
For example, if you specify the search domain apple.com, typing “store” in your web browser takes you to store.apple.com. Or, if you use campus.university.edu as a search domain, you can type “server1” in the Connect To Server dialogue in the Finder to connect to server1.campus.university.edu.
On your Mac, choose Apple menu > System Preferences, then click Network.
In the list at the left, select the network connection service you want to use (such as Wi-Fi or Ethernet), then click Advanced.
Click DNS, then click the Add button at the bottom of the DNS Servers list. Enter the IPv4 or IPv6 address for the DNS server.
Click the Add button at the bottom of the Search Domain list, then enter the search domain — for example, apple.com.
When you’re finished, click OK.
Domains are searched in the order you list them; the search stops when a valid name is found.
To search a name hierarchy, use search domains of varying scope. For example: building.campus.university.edu, campus.university.edu, and university.edu.