When an Internet Service Provider (ISP) provisions Internet service, the ISP will typically provide you with two DNS servers – a primary and a secondary (backup) DNS server to use for DNS resolution. If you are experiencing issues with your ISP’s DNS servers, you’ll want to check to see if both DNS servers are problematic (ex: DNS server latency, DNS server times out, errors resolving domain names or hostnames to their respective public IP addresses, etc.).
If your ISP’s primary DNS server is problematic but the secondary (or backup) DNS server is working properly, you can switch the priority between your primary and secondary DNS servers. If your router is setup for DHCP, you’ll need to make the DNS changes on the router and then reboot your computers and devices to ensure they receive the updated DNS changes. If your computer is setup using static IP addressing, you can update the DNS priority in the network settings of your OS. Keep in mind that you should report any issues with your ISP’s DNS servers to the ISP. This will ensure your ISP’s network engineers are aware of the issue, investigate and work towards a resolution.
If both of your ISP’s DNS servers (primary and secondary) are problematic, you can switch to a pair of Public DNS servers offered by reputable providers. Google, CloudFlare and OpenDNS are three popular providers that offer Public DNS servers which you may use in lieu of your ISP’s DNS servers.
The Public DNS servers for Google, CloudFlare and OpenDNS are listed below.
Google Public DNS
CloudFlare Public DNS
OpenDNS Public DNS
Whether you choose to use your ISP’s DNS servers or Public DNS servers from Google, CloudFlare, OpenDNS or other reputable providers is up to you; however, if you are experiencing issues with your ISP’s DNS servers, know that there are reliable Public DNS servers available from reputable providers which you can use on an interim basis until your ISP can resolve the issues with their DNS servers.