Most of the time, your ISP automatically assigns a primary and secondary DNS server when your router or computer requests network information via DHCP. But what if those ISP-provided DNS servers aren’t reliable or you’re troubleshooting an issue and you suspect that DNS might not be working properly?
How Does DNS Work?
The Domain Name System (DNS) is a database that handles translating a fully qualified domain name into an Internet Protocol (IP) address. Most computer networks will have at a minimum one DNS server to handle queries which are commonly referred to as the “name server.” It will store a listing of all of the IP addresses stored on the network as well as a cache of the IP addresses recently accessed outside of the network. On any given network, a computer only needs to know the location of one name server. When a computer goes to lookup an IP address that is not stored on the computer, it will check with the Name Server. The Name Server will see if it is addressed locally, but if someone on the network has recently requested the same address the IP address will be retrieved from the server’s cache.
Each of these cases results in little wait for a response. If the address has not been requested recently, then the Name Server will perform a search by querying two or more name servers. These queries can take anywhere from seconds to a minute based on the network speed. If no resolution is found, an error message is returned to the user.
Public DNS Servers
The following are public DNS servers available for free use at the time of this writing. Before changing your personal or work computer DNS settings, ensure that you note the specifics for the legacy system you are changing in the event the free service has issues or is no longer available.
- Google Public DNS
- Level 3 Communications (Broomfield, CO, US)
- Verizon (Reston, VA, US)
- GTE (Irving, TX, US)
- One Connect IP (Albuquerque, NM, US)
- OpenDNS (San Francisco, CA, US)
- Exetel (Sydney, AU)
- VRx Network Services (New York, NY, US)
- SpeakEasy (Seattle, WA, US)
- Sprintlink (Overland Park, KS, US)
- Cisco (San Jose, CA, US)
- ClearCloudPreferred DNS server: 18.104.22.168Alternate DNS server: 22.214.171.124
- DNS Advantage
126.96.36.199 and 188.8.131.52
- Norton DNS
Norton provides three DNS servers based on types of security provided. All policies block malware, phishing and scam sites.
Pornography includes sites that contain sexually explicit material.
Non-Family Friendly (for families with children) includes sites that feature: mature content, abortion, alcohol, crime, cult, drugs, gambling, hate, sexual orientation, suicide, tobacco or violence.
A – Security (malware, phishing sites and scam sites)
Preferred DNS: 184.108.40.206
Alternate DNS: 220.127.116.11
B – Security + Pornography
Preferred DNS: 18.104.22.168
Alternate DNS: 22.214.171.124
C – Security + Pornography + Non-Family Friendly
Preferred DNS: 126.96.36.199
Alternate DNS: 188.8.131.52
- Comodo Secure DNS
SecureDNS helps users keep safe online with its malware domain filtering feature. SecureDNS references a real-time block list (RBL) of harmful websites (i.e. phishing sites, malware sites, spyware sites, and parked domains that may contain excessive advertising including pop-up and/or pop-under advertisements, etc.) and will warn you whenever you attempt to access a site containing potentially threatening content.
I have to admit Google DNS servers are fastest among public DNS servers.