Your DNS server settings need to be changed so that it points to 138.37.216.10 and 138.37.217.10 which are the Cisco Umbrella DNS resolvers.
Instructions on how to do this are below. Please select the correct instructions based on your operating system.
Microsoft Windows: https://www.lifewire.com/how-to-change-dns-servers-in-windows-2626242
Mac OS: http://osxdaily.com/2015/12/05/change-dns-server-settings-mac-os-x/
There are a number of different Linux distributions available therefore making the change will depend on identifying which version you are using. This can be achieved in a number of ways: https://www.howtoforge.com/how_to_find_out_about_your_linux_distribution. Once you know what distribution you are using, you’ll need to take a look at documentation for that Linux distribution to change your DNS name server settings. Instructions for popular Linux distribution documentation can be found here:
Once this has been done, you can test if this works using the DOS command prompt or terminal and typing ‘nslookup www.google.com’ or any other known domain to see if it resolves successfully using either 138.37.216.10 or 138.37.217.10.
The result should look like this.
If you require further assistance please contact IT Services