What is Secondary DNS?

What is Secondary DNS?


Secondary DNS is a technical term for Domain Name System (DNS) that can be used in case there’s an outage or disruption on your main domain name server at any point in time. As we all know, DNS plays a major role in directing traffic across the internet by translating website names into IP addresses, which are easier for computers to understand.

Secondary DNS is needed primarily for load balancing. If more than one or two websites are hosted by your web hosting company then there may be a possibility that all the website’s connections will go to load balancers. If Secondary DNS isn’t deployed in this case, users accessing each website may get different IP addresses of servers for every request resulting in performance issues.

What are secondary DNS records?

A secondary DNS record is a record for a hostname that’s managed as an alias to another original name. If the original domain name is deleted or changed, the secondary can still be used with no disruptions in service.

Secondary DNS records are created to allow a hostname to have more than one domain assigned to it. This is useful when you want to change the primary or canonical name of a site without breaking links. Instead, you can create secondary names for the site before changing them over time until they are no longer necessary.

How many types of secondary DNS records are there?

There are two types of secondary DNS records: the CNAME record and the MX record. CNAME stands for Cannae name. The MX record stands for “mail exchange”.

A Canonical Name or CNAME record is used to point from one domain name to another, usually from a subdomain to its parent domain. The most common reason for using a CNAME instead of an A Record with a wildcard is to avoid having to manage service downtime during a switchover: if the name of service changes, only its CNAME needs to be changed.

MX records are used in email servers to point the domain name to one or more mail servers responsible for receiving and delivering email for that domain. The lower the number, the more preferred is this server.

How do they work?

A secondary DNS server is a DNS server that stores an updated list of IP addresses for the computers on the Internet. A secondary DNS server can store both IPv4 and IPv6 addresses.

When a domain name needs to be resolved into an IP address, the computer requests that information from a DNS server. The first DNS server to respond with the location of the IP addresses is called a primary DNS server. The request for an IP address is then sent to the primary DNS server. This process can take several seconds – sometimes up to several minutes. The IP address returned by the primary DNS server is cached on the secondary server, however, to ensure that it can be quickly looked up should another request for the same IP address come through again.

If a computer has set up multiple DNS servers to use in case one fails, any other computers using this machine as their DNS server will query the secondary DNS server for an IP address. They will also use the cached information to ensure that they get all of their requests answered quickly. If another computer using this machine as a DNS server needs to lookup an IP address, it will be added to the list on the original computer’s secondary server.

Why would you want to use them?

There are many reasons for using Secondary DNS. One of the most common reasons for running multiple DNS servers is to provide increased redundancy and availability. Other common reasons for running secondary name resolution systems include providing higher performance or distributing the workload to different networks linked by WAN links, geographic regions, etc.

Another common reason companies might want to use secondary DNS systems is for off-boarding purposes. Let’s say you’re a company that has recently acquired another and the new acquisition uses an internal DNS system and it would take too long to get their internal DNS ready for production use with your environment. A workaround could be to set up a secondary DNS server for this purpose so you can off-board the old DNS servers slowly.

When should you not use them?

You should not use a secondary DNS on your computer if the network you’re on is unreliable. Also, if you have more than one computer and need to access the same website from different networks, then secondary DNS will not work for you. This is due to the fact that you will have multiple IP addresses, each of which will point you to a different secondary DNS. The end result will be that you’re still unable to access the website – because your computer does not know which secondary DNS to choose from.


Secondary DNS is a way to speed up the process of loading websites. It’s primarily used for caching purposes, which essentially means that your browser stores certain files from popular sites on its own hard drive so that it doesn’t have to constantly fetch them over and over again. The best time to use secondary DNS is when you want faster load speeds but don’t plan on changing location much while viewing the site – whether because you’re at home or in an office building with a fast internet connection. However, if you’ll be moving locations often during browsing sessions (such as using public wifi), then this won’t work well for you since each new network will require downloading all those cached files anew.<br><br>Secondary DNS can also help bypass geographical restrictions since it can disguise your true location. This is especially useful for people who travel often and want to access geo-blocked sites while abroad. Using secondary DNS will allow you to unblock websites like Netflix, Amazon Prime Video, Hulu, BBC iPlayer, and more without having to change any network settings or install additional software on their devices.

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