DNS stands for Domain Name System and is a component of the Internet. The system is responsible for converting a domain name into an IP address. The DNS works by utilizing DNS servers. An IP address is an extended digital code that identifies each computer system on the Internet. An IP address is unique for each domain name. A DNS server converts the domain name to an IP address, using a search table to determine the IP address.
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Domain name system
The Domain Name System (DNS) is the system of identifying network resources on the Internet. It organizes information into resource records containing type, class, and expiration time. These resource records are stored in a distributed database and are accessed by name servers. Each domain has an authoritative DNS server that publishes information about its domain and its subordinate domains. These servers are referred to as root name servers, and when a user searches for a TLD, the DNS resolver queries these authoritative name servers.
Paul Mockapetris first developed DNS in 1983. The principles he outlined are still underlying the system today. The Internet Engineering Task Force is responsible for maintaining standards for DNS, which is why you’ll find these standards in the DNS directory. DNS servers store information for domain names and their associated domains and communicate with each other regularly.
Recursive DNS queries
A recursive DNS query is a process by which a client queries a DNS server recursively. In this process, a client queries a DNS server several times until it receives an answer that satisfies its request. This differs from an iterative DNS query, which must be explicitly requested each time. The first query authorizes all subsequent DNS queries.
A recursive DNS query fills up the server’s zone file cache and consults other authoritative DNS servers. The client request does not leave the server and remains in contact with it until the request cannot be resolved. This results in a DNS query error.
CLASS of a record
The CLASS of a record in DNS complete forms is a two-byte field that specifies the type of record. Different types of records can have different purposes. For example, an A record translates a domain name into an IPv4 address, while a CNAME record maps an alias to its canonical name.
The CLASS of a record is usually listed before the name. In other words, it tells the system which domain it is related to and which part is related to the name. For example, “www.com” would be a subdomain of “.org.” In addition, the RNAME field specifies the email address of the zone’s owner. However, if the name field is empty, the server does not process it. Another type of record is the SRV record, which stores the port and host information for internet service. Some internet protocols require that the SRV record be valid. It could also contain a service symbol.
The TTL (time-to-live) of a DNS record is specified in seconds. This value is used to determine how long the record must stay valid. In addition, the NS record is a mandatory record for zone files. It tells the DNS server which domain belongs to and who is responsible for forwarding the domain to another zone. Another essential record type is the TXT record, which contains text intended for human users. It may contain information about the domain company.
Flag field
The Flag field in DNS form contains various bits representing different kinds of information. The Query/Response Flag specifies the type of message a client or server sends. The field is set to zero when the message is a query and to one when it changes to a response.
The Flag field also called the parameter field, lets the server or client know what kind of query is being sent. It contains information on how the query and response should be handled. If this field is omitted from the message, the query will be redirected to the wrong server. This can cause a lot of problems.
