What are the differences between DNS and DHCP

What are the differences between DNS and DHCP? This article will introduce to you how DNS and DHCP work respectively, so that you can understand the difference between DNS and DHCP. I hope it will be helpful to you.

What is DNS?

DNS (Domain Name System) is a mechanism that provides a directory lookup service that maps the names of hosts on the Internet to their unique numeric addresses (logical addresses).

Traditionally, mapping is done using hosts files, which have details such as names and addresses. These hosts files are stored on each host and updated periodically from the main hosts file. Whenever a program or user needs to map a name to an address, the host queries the hosts file and finds the mapping. However, with today's large numbers of hosts connected over the Internet, this mechanism would be extremely unreliable.

How does DNS work?

When a user wants to use a file transfer client to access a file transfer server running on a remote host, the user only knows the file transfer name. To establish a connection, the TCP/IP suite must require the IP address of the file transfer server. The diagram given illustrates the step-by-step working of DNS.

What is DHCP?

DHCP is the abbreviation of Dynamic Host Configuration Protocol. It is mainly responsible for quickly and automatically assigning IP addresses in the network. Additionally, it is used to configure the correct subnet mask, default gateway, and DNS server information on the device.

How does DHCP work?

DHCP works by leasing IP addresses and IP information to network clients for a period of time. To do this, the DHCP client must interact with the DHCP server through a series of DHCP messages, mainly including DHCP DISCOVER, DHCP OFFER, DHCP REQUEST and DHCP ACK. As shown below, the client computer sends a broadcast packet DHCP DISCOVER, including the computer's name and MAC address so that the DHCP server can respond to it.

The server receives the DHCP DISCOVER and responds to it with a DHCP OFFER message. The client then responds with a DHCP REQUEST, which means it wants to accept the configuration sent by the DHCP server. After receiving this DHCP REQUEST message, the DHCP server will send a DHCP ACK to tell the client that it can now use the IP address assigned to it.

The difference between DNS and DHCP

1. The essential difference

DNS is an address resolution mechanism used to resolve and recursively resolve addresses to name or name addresses to hosts.

DHCP is a protocol used to statically or dynamically assign IP addresses to hosts.

2. Related protocols

DNS only supports UDP protocol; DNS can support both TCP and UDP protocols.

3. Difference in port numbers

DNS uses port number 53, while DHCP can use 67 or 68.

4. The operations performed by the server are different

The DNS server is responsible for accepting queries through the client and responding to the client and replying results.

The DHCP server is responsible for assigning temporary addresses to client computers for a period of time and then extending the lease as needed.

5. Differences in working methods

DNS follows a certain hierarchy that does not allow all domain names to be stored in one place. is to break it down into subdomains and then store specific information on specific servers. Therefore, it is conducted in a decentralized manner.

DHCPThe server configures the client's IP address from the IP address pool and centralizes handles all tasks, if the DHCP server is not directly connected to the client, it uses a router to receive it DHCP broadcast and forward it to the DHCP server.

Summary:

The DHCP server assigns IP addresses to client computers, and the DNS server resolves them. They are two essential technologies developed for us to use the network or the Internet conveniently. Additionally, both DHCP and DNS are essential tools in a network administrator's toolkit.

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