The Domain Name System (DNS)
The Domain Name System (DNS) is a hierarchical decentralized naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates more readily memorized domain names to the numerical IP addresses needed for the purpose of locating and identifying computer services and devices with the underlying network protocols. By providing a worldwide, distributed directory service, the Domain Name System is an essential component of the functionality of the Internet.
Types of DNS:-
1)Generic Domain:
2)Country Domain:
3)Inverse Domain:
DNS Overview
• On the Internet, the Domain Name System (DNS) associates various sorts of information with domain names – Serves as the “phone book” for the Internet – Translates human-readable computer hostnames into IP addresses
• Required by networking equipment to delivering information – Also stores other information
• Such as the list of mail exchange servers that accept email for a given domain.
• By providing a worldwide keyword-based redirection service, the Domain Name System is an essential component of the modern Internet
DNS:-
• It stands for domain name system. • The naming scheme used in the internet is called
DNS. • To identify an entity the internet uses the IP address.
• Which identifies connection of computer to internet.
• But user to use names of numeric address because to remember numeric address are difficult compare to names.
• We need a system that can map a name to an address or an address to name.
• So, the naming scheme used in the internet is called the DNS.
• In DNS name must be unique because the address are unique.
• In DNS names are defined in an inverted tree structure with the root at the top.
- DNS Record Viewer - A, AAAA, CNAME, MX, NS, PTR, SOA, SRV, TXT
- A list of most common records is provided below:
- Address Mapping records (A) …
- IP Version 6 Address records (AAAA) …
- Canonical Name records (CNAME) …
- Host Information records (HINFO) …
- Integrated Services Digital Network records (ISDN) …
- Mail exchanger record (MX) …
- Name Server records (NS) …
- Reverse-lookup Pointer records (PTR)