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Root server

Root server definition

A root server is a crucial component of the DNS infrastructure that helps to resolve domain names into IP addresses, which computers use to communicate with each other on the internet.

There are 13 root servers in the world, labeled A through M, that are operated by different organizations and located in different geographic regions. These servers store the root zone file, which contains information about the top-level domains, like .com, .org, .net, and so on.

When a user types a domain name into their browser, the request is sent to a recursive DNS resolver, which then queries the root server to find out which authoritative name server is responsible for the requested domain. The resolver then queries the authoritative name server for the IP address associated with the domain name and returns the result to the user's browser.

See also: DNS query, DNS record, DNS resolution

What happens if a root server is down?

If a root server is down or experiencing issues, the other root servers in the network can take over its responsibilities to ensure that the DNS system remains functional. Since there are 13 root servers distributed worldwide, the failure of a single root server is unlikely to have a significant impact on the overall performance and availability of the DNS system. However, if multiple root servers were to fail simultaneously, it could potentially cause disruptions in the DNS system and make it difficult to access websites and other online services.