DNS - adaley0518/Tech_Journal GitHub Wiki
What is DNS?
- DNS is a method that allows humans to interact with computers by name rather than an IP. Root servers begin the hierarchy with TLD's (com, org, edu etc). This can branch out further depending on the root servers. After the root servers, comes the TLD name servers. These DNS servers may have referrals to subdomains (Microsoft, Google).
- DNS has 3 types of DNS queries:
- Iterative: when this query is sent to a DNS server, the DNS server returns an answer to the client. The responses include:
- requested resolved name
- referral to a different DNS server to find the provided information the client requested.
- Recursive: when this query is sent to a DNS server, the DNS server has to return one of two responses:
- resource record containing the IP address associated with the hostname requested
- error message stating the hostname or domain does not exist for any DNS server
- Inversive: the DNS resolver sends a request to a DNS server to resolve the hostname associated with a known IP address. Must search through all domains to provide the correct answer.
- Iterative: when this query is sent to a DNS server, the DNS server returns an answer to the client. The responses include: