Photo: Winston Chen on Unsplash
DNS vs DHCP: what is the difference?
In short: DNS (the Domain Name System) works like the internet's phone book, turning names such as fmtechub.com into IP addresses. DHCP (Dynamic Host Configuration Protocol) gives each device its own IP address and network settings when it joins. Your router usually handles DHCP and passes DNS questions on.
DNS vs DHCP in one sentence
DNS answers the question "what is the address of this website?", while DHCP answers "what address should this new device use on this network?".
Side-by-side comparison
| Feature | DNS | DHCP |
|---|---|---|
| Question it answers | What IP address is this name? | What settings should this device use? |
| When it is used | Every time you visit a site or app by name | When a device joins or reconnects to a network |
| Gives out | IP addresses for names | An IP address, gateway and DNS server for the device |
| Usual port | UDP 53 | UDP 67 and 68 |
| Who runs it at home | Your provider or a public DNS service, via the router | Your router |
| Sign it is broken | Websites by name fail, but numbers work | Device has no address or a 169.254.x.x address |
What is DNS?
DNS lets you type names instead of numbers. When you open a website, your device asks a DNS server for the address, gets the reply and then connects. Answers are remembered for a while to save time. Because DNS is involved in nearly everything you do online, a DNS problem can make it look as if "the internet is down" even when the connection itself is fine. Our article What is a domain name? explains the names side.
What is DHCP?
DHCP saves everyone from typing network settings by hand. When your phone joins Wi-Fi, it broadcasts a request; the router replies with an offer of an address; the phone requests it; the router confirms. Engineers remember this as DORA: Discover, Offer, Request, Acknowledge. The address is "leased" for a time and renewed automatically. DHCP also tells the device which DNS server to use, which is where the two services meet.
Which one should you use?
You need both, and at home they are set up for you. If a device cannot connect at all, think DHCP: restart the device and router. If a device is connected but websites will not load by name, think DNS: try restarting the router, or check whether a particular site is down. IT teams often reserve fixed DHCP addresses for printers and servers so they are always easy to find.
Common mistakes and myths
- "DNS gives my device its IP address." That is DHCP; DNS finds addresses of other places.
- Setting a fixed address by hand that is also in the router's DHCP range can cause two devices to clash.
- "Changing DNS makes my internet faster." It can make lookups slightly quicker but does not increase your line speed.
- Forgetting that DHCP also hands out the DNS server setting.
Learn more
Key takeaways
- DNS turns names into IP addresses.
- DHCP gives devices their address, gateway and DNS settings.
- Websites failing by name points to DNS; no address points to DHCP.
- At home, the router handles DHCP and forwards DNS questions.
© 2026 FM TecHub. Original content written for FM TecHub. Share the link freely; please don't copy the text elsewhere without permission.