During a DNS lookup, which server is contacted after memory/cache?

During a DNS lookup, which server is contacted after memory/cache?

• A. Root server
• B. TLD server
• C. Hosting server
• D. Cache

Answer: (A)

When a DNS lookup can’t be answered from memory or local cache, the resolution starts at the top of the DNS hierarchy. Root servers are contacted first because they are the directory of the Internet’s naming system: they don’t provide the final IP, but they know where to find the next step for any domain’s top-level domain (like .com, .org, or .net). The root server replies with the address of the appropriate TLD name servers, and those servers then direct the resolver to the authoritative server for the specific domain. The hosting server isn’t involved in this referral chain, and a cache is not a server but a storage area used to speed up future lookups. Caching can avoid contacting any servers if the IP is already stored locally or by the resolver.

When a DNS lookup can’t be answered from memory or local cache, the resolution starts at the top of the DNS hierarchy. Root servers are contacted first because they are the directory of the Internet’s naming system: they don’t provide the final IP, but they know where to find the next step for any domain’s top-level domain (like .com, .org, or .net). The root server replies with the address of the appropriate TLD name servers, and those servers then direct the resolver to the authoritative server for the specific domain. The hosting server isn’t involved in this referral chain, and a cache is not a server but a storage area used to speed up future lookups. Caching can avoid contacting any servers if the IP is already stored locally or by the resolver.