DNS Re-address Project nears completion


In an effort to further secure and reduce the complexity of U-M networks, ITS Infrastructure has worked for the past year with unit IT representatives to change the IP addresses of U-M’s domain name system (DNS) resolver servers from public to private. The goals of the project were to:

  • Improve security by reducing internet threats that exploit DNS resolvers.
  • Reduce network complexity by consolidating DNS server addresses from nine public IP addresses to two private IP addresses.
  • Reduce maintenance costs by providing only two DNS server addresses to campus for DNS resolution.

To successfully complete this effort, systems across U-M relying on DNS resolver services that ITS provides to campus will need to use the new private IP addresses listed below.  To date 99.5% (175,000+) of systems at U-M are using the new private DNS resolver IP addresses. ITS has been doing active outreach trying to connect with owners of the remaining systems still using the old resolver addresses to ensure their systems update  to the new DNS resolver IP addresses.

On February 24, 2018, ITS will turn off the nine public IPs for the public DNS resolvers. At that time all systems must be configured to the new private IP addresses for DNS resolver servers:

New private IP addresses for DNS resolver servers:

  • – Primary DNS resolver address
  • – Secondary DNS resolver address

For those that fail to make this change, a redirect webpage with instructions on how to change to  resolver IP addresses will be provided starting February 24. For the .5% of systems that remain to be reconfigured to use the new private IP DNS resolver addresses, DNS resolver services will no longer function after February 24 without updating DNS resolver addresses to the new private IP addresses.

A project overview, with list of old DNS resolver addresses that will be turned off, provides additional detail. For questions or concerns, contact Hostmaster@umich.edu.  ITS Infrastructure will be happy to work with you, if you need additional assistance.