DHCP vs DNS: What’s the Difference?

DHCP and DNS: if you’re anything like most not-so-tech-savvy people, this can be quite a head-scratcher. And even if you have an inkling as to what they mean, it’s possible you’ve yet to fully wrap your head around these two networking technologies. 

If so, then this article will provide you with all the information you need to understand the ins and outs of DHCP and DNS, shedding light on the differences between them. Let’s dive right in!

DHCP vs DNS: Side-by-Side Comparison

Feature	DHCP	DNS
Acronym meaning	Dynamic Host Configuration Protocol	Domain Name System
Developed by	Internet Engineering Task Force in 1997	Paul Mockapetris in 1983
Functionality	Assigns IP addresses to devices	Translates domain names into IP addresses
Security	67 or 68	53
Communication Protocol	UDP	UDP or TCP
Hierarchy	Decentralized; no hierarchy	Centralized; hierarchical

DHCP vs DNS: What’s the Difference?

First things first, let’s define what we mean by DHCP and DNS.

What’s DHCP?

DHCP stands for Dynamic Host Configuration Protocol and is used to automatically assign IP addresses and other configuration information, such as subnet masks and default gateways to devices on networks. But why do we need an IP in the first place?

When a device joins a network, it needs an IP address to communicate with other devices on the network. DHCP assigns a unique IP address to each device on the network, ensuring that no two devices have the same IP address. It does so automatically, making it easy for devices to communicate with each other and access network resources without conflicts.

Think about it: if every device had a static IP address set manually by someone on the network team, it would be incredibly difficult to manage large networks with hundreds or even thousands of devices. DHCP makes things much easier by dynamically assigning addresses from a pool of available ones whenever a new device connects.

What’s DNS?

The Domain Name System (DNS) translates domain names into IP addresses with the help of a DNS server. A DNS server is like a phone book for the internet. It translates human-readable domain names (like google.com) into numerical IP addresses (like 172.217.164.46) that computers use to identify each other on the network.

Without DNS, we would have to remember long strings of numbers instead of easy-to-remember domain names when accessing websites or connecting devices on our networks. So, next time you type in a website name into your browser’s address bar, remember that behind the scenes, your computer is using DNS to translate that name into an IP address.

It essentially resolves the domain name into the IP address of the server that hosts the website. This allows your device to communicate with the server and access the website’s content.

Thus, both deal with IP addresses in some way, but serve different purposes within a network infrastructure. Now that the definitions are out of the way, let’s look at some other major differences between DHCP and DNS.

Port Numbers

Another difference between DHCP and DNS is their use of port numbers. DNS uses port number 53 to communicate with other devices on the network, while DHCP can use either port number 67 or 68.

Port numbers are used to identify specific applications or services on a network. By using different port numbers, multiple applications can run on the same network without interfering with each other.

Communication Protocol

DHCP and DNS use different communication protocols. DHCP uses the super-fast User Datagram Protocol (UDP) to assign IP addresses to devices on a network. This connectionless protocol sends data packets without establishing a connection first. 

Think of it like a radio broadcast, which sends data out to many listeners without checking whether each listener received the data correctly. The broadcast approach makes UDP faster and more efficient for tasks like streaming, where occasional data loss is acceptable. It’s fast and efficient because it doesn’t waste time setting up connections before sending data.

On the other hand, DNS can use both UDP and TCP (Transmission Control Protocol) protocols. TCP requires a connection to be established before data can be sent, similar to how making a phone call requires establishing a two-way connection first. While this may take slightly longer than UDP, it ensures that your data is transmitted reliably and accurately.

Hierarchy

DNS is a hierarchical system that consists of multiple levels. That means it’s organized like a tree, with top-level domains like .com and .org at the top, and more specific domain names like google.com below them. 

The root servers at the very top store information about these top-level domains, while the authoritative name servers below them store information about specific domain names. DHCP, on the other hand, does not have a hierarchical structure — it doesn’t need one, as all it does is simply assign IPs to devices on the network.

Thus, DNS is a centralized system that works in a hierarchical manner to translate domain names into IP addresses. Meanwhile, DNS is decentralized and operates on a client-server model where the server assigns IP addresses to clients requesting them.

DHCP vs DNS: 6 Must-Know Facts

1. The Domain Name System was created in 1983 by Paul Mockapetris and has been continuously updated since then, with new features such as DNSSEC security extensions being added over time.
2. DHCP was developed by the Internet Engineering Task Force (IETF) under the RFC 2131 specification which was published in 1997. Since then, there have been several revisions and updates to the protocol such as RFC 2132, which introduced additional options that could be configured on DHCP clients, like the default gateway and DNS servers.
3. DNS uses the A record to map domain names to their corresponding IP addresses. This mapping allows devices to locate resources on the internet using domain names rather than IP addresses.
4. DHCP can be used to assign both IPv4 and IPv6 addresses to devices on a network.
5. DHCP servers can also assign other network configuration parameters, such as subnet masks, default gateways, and DNS server addresses, while DNS only translates domain names to IP addresses.
6. Intranets use both DHCP and DNS to manage their internal network services.

DHCP vs DNS: Which One Is Better? Which One Should You Choose?

Technically, the answer isn’t as simple as one being better than the other, as both serve different purposes in the networking world. That’s why choosing one over the other wouldn’t make sense.

However, if you’re setting up a new network, then you’ll definitely need DHCP to assign IP addresses to devices. As we saw, it’ll save you time and effort by automating the process of assigning IP addresses and default gateways.

Once you already have DHCP working and now need to use custom domain names, then you will need DNS to translate the domain names into IP addresses. You can set up your own DNS server or you can use a public DNS service like Google DNS or OpenDNS.

It’s worth noting that routers often have built-in DHCP and DNS functionality, so you may not need to set up separate servers for each. Check your router’s documentation to see if it supports these services and how to configure them.