Many people still ignore the importance of the Domain Name System (DNS) in our daily lives. The Internet gets the complete spotlight, but it totally relies on the DNS and its different components, the recursive DNS server, for instance. Let’s know the main characteristics of this important DNS component.
Recursive DNS server – Main characteristics
A recursive DNS server has an important job. It is in charge of searching the necessary data to respond to clients’ DNS requests.
When a user (potential client) requests a domain name through her or his browser, a recursive DNS server will look for the associated IP address of that domain. Without this information, the domain can not be loaded for the user. The recursive DNS server won’t stop its search due to one of its main characteristics, “recursion”. In the computing science field, recursion means a process or solution that repeats itself the necessary number of times to reach a specific goal. So the recursive server will look for the IP address until it finds it.
Once the DNS recursive server obtains the IP address, it will deliver it to the user’s browser. Then, and only then, the domain can be loaded by the user.
Another characteristic of a DNS Recursive server is that it has two ways to execute its job.
1. It can look for the DNS information needed to respond to the DNS requests within its cache. There is a chance for information to be kept available there. It will depend on the time-to-live (TTL) value previously set on the DNS record. If this TTL has not expired, the recursive will get the information and respond to the user very fast.
This is possible because the recursive DNS server’s cache can keep information for a specific period of time, not permanently. How long? The defined time on the TTL of DNS records (decided by administrators).
2. If the DNS record has never been inside the cache or the TTL has already expired, the DNS recursive server won’t find the necessary IP address in its cache. Then, the recursive will use a “B” plan. That means it will ask other servers for information. Its search must lead it to the exact, authoritative server that has the DNS information. It takes longer than checking in the cache, but it is an effective way to obtain DNS information.
When we say “longer”, we talk in milliseconds. It is a fast process.
To summarize, DNS recursive servers are essential for the DNS resolution process. Without them, DNS requests can not be answered. Therefore users can not load domains.
There are plenty of Recursive servers working 24/7, worldwide. Every user requesting a domain is a call to a recursive server to start a search.
DNS recursive servers search that is their duty, search for DNS information. They can keep DNS information but only temporarily.
Recursive DNS servers are essential for users to reach your online business! Walking through their main characteristics, you can better understand their value.