What are the three parts of DNS and what is the role of each part

A brief understanding of DNS, explain the general working principle of DNS, and what is DNS hijacking, if there is any problem, welcome to leave a message to correct, if you think this is helpful to everyone, don't forget to triple it

Namespace, nameservers, distributed databases.

Step 1: The client makes a DNS request and sends the request to the local name server.

Step 2: When the local name server receives the request, it will query the local cache first, and if there is a hash entry in the record, the local name server will directly return the query result.

Step 3: If the local cache does not have this record, the local nameserver will send the request directly to the root nameserver, and then the root nameserver will return the address of the primary nameserver of the queried domain (the root sub-Lianghe town domain) to the local nameserver.

Step 4: The local server sends a request to the name server returned in the previous step, and then the server receiving the request queries its own cache, and if there is no such record, it returns the address of the relevant subordinate domain name server.

Step 5: Repeat step 4 until you find the right record.

The main functions of DNS include the following three:

Namespace: Define a namespace that includes all possible host names.

Domain name registration: Guarantee the uniqueness of each host's domain name.

DNS advantages:

The full name of DNS is Domain Name Server, a program that stores a table of domain names and corresponding IP addresses to resolve the domain name of messages.

A domain name is the name of a computer or group of computers on the Internet that identifies the computer's electronic location (and sometimes geographic location) during data transmission. A domain name is a string of names separated by dots, usually containing the name of the organization, and always includes a two- or three-letter suffix to indicate the type of organization or the country or region in which the domain is located.

It does not take a long time to resolve the domain name, because Internet access providers, such as Beijing Telecom and Henan Telecom through Sunshine DNS, usually cache a lot of DNS records of domain names in their DNS servers, and then make network allocations according to the user's location.

In this way, when the user of the access provider wants to open a web page, the server of the access provider does not need to query the domain name database, but directly uses the DNS records in its own cache, so as to speed up the user's access. This is its greatest advantage.

DNS is a service that links domain names and IP addresses, with a DNS server bend to do respect, you don't need to enter an IP address to access a**, you can access by entering**Hu Qing.

In the first process, the client makes a DNS request and sends the request to a local name server.

In the second process, when the local nameserver receives the request, it will query the local cache first, and if there is such a record, the local nameserver will directly return the query result.

In the third process, if the local cache does not have the record, the local nameserver sends the request directly to the root nameserver, which then returns the address of the primary nameserver of the queried domain (a subdomain of the root) to the local nameserver.

In the fourth process, the local server sends a request to the name server that returns to the next step, and then the server that receives the request queries its own cache, and if there is no record, it returns the address of the relevant subordinate name server.

For the fifth process, repeat the fourth step until you find the right record.

In the sixth process, the local nameserver saves the returned results to the cache for the next use, and also returns the results to the client. Old code.

To put it simply, I can't visit without him.

Have domain knowledge you need to know!

Key features:

Easy to remember. domain

name with.

Easy to remember. ipaddress.

surface to perform DNS services.

web hosts.

It is called dnsserver basic pass.

I recognize DNSDOMAIN

name conversion.

ipaddress

Use the checkup again.

ipaddress

Connections (colloquially called.

to parse) factual IP

address transformation.

domain

name function.

Use login

UNIX workstations.

The workstation does a reverse lookup.

Connected into (commonly known as.

Reverse analysis. The domain name consists of two.

or two-word construction. The space is separated by dots on the right.

The number of top-level domains is called.

See Top-level domains and their uses.

com - for commercial establishments.

See any top-level domains.

Enroll. com

Proform domain name. net--

Originally used in network organization.

Example of a special network service provider.

Repairers are now any.

Enroll. net end.

Domain name. org--

Various organizations, including non-profit organizations, are cashed.

Register for any. org

Ending domain name. Home ** consists of two.

Alphabetic top-level domains.

cn, uk, the home ** top-level domain (cctlds), its. cn

Dedicated top-level domain name, the registration of which is managed by CNNIC, ending with CN.

Second-level domain name me.

Abbreviated as the domain name.

Register a top-level domain name.

Second-level domain names. Rules and policies with the same family.

Policies govern your registration.

You should check with your domain name registrar to find out what is going on.

Conditions of registration and registration related to registration.

Terms for certain domain name registrars except.

Offer. com,net

org end.

Domain Name Registration Services.

Outside, provided. Home**TLD.

ICANN is not registered.

Specially accredited registrars.

Home**TLD.

Sign up for the service. Second-level domain top-level domain level I.

Said second-level domain name.

Domain name registration. com end.

Top-level domains. Provide second-level domain names.

Domain name form can.

DNS is a hierarchical distributed system consisting of multiple DNS servers. A DNS server is any computer registered to join DNS. It has an index of domain names and IP addresses, and when requested, it can tell you the current IP address associated with the domain name.

The full name of DNS is Domain Name System or Domain Name Service.

Its main function is to "translate" familiar addresses (domain names) into IP addresses that computers can understand. This process is called DNS domain name resolution. DNS servers are typically funded by Internet Service Providers (ISPs) such as telecom mobile broadband.

They have set up many groups of DNS servers across the country.

The role of a DNS server is to resolve domain names into IP addresses.

In order to access a server on the Internet, it must also be done through an IP address, which is the process of converting a domain name back into an IP address. A domain name corresponds to an IP address, and an IP address can correspond to multiple domain names. So multiple domain names can be resolved to a single IP address at the same time. Domain name resolution needs to be done by a dedicated domain name resolution server (DNS).

The resolution process, for example, a domain name is: is to see this current http service, if you want to access **, you need to parse, first in the domain name registrar through a dedicated dns server to a web server to resolve to a fixed IP of a web server, and then, through the web server to receive the domain name, the domain name to this server.

People are accustomed to memorizing domain names, but machines only recognize each other's IP addresses, and the domain names correspond to IP addresses, and the conversion between them is called domain name resolution, and domain name resolution needs to be completed by a dedicated domain name resolution server, and the whole process is carried out automatically.

a: Resolve the domain name you entered to an IP address.

a Resolve the domain name to an IP address.