SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/aplus-dns-port

Which port number does DNS use?

Port 53 is for the Domain Name System.

Start playing free

  1. 67
  2. 53 ✔
  3. 80

Why: DNS answers name lookups on port 53. Port 67 is the DHCP server and 80 is plain HTTP. Port 53 is used over both UDP and TCP.

Huh, didn't know that: The IANA registry lists port 53 as 'Domain Name Server' for both TCP and UDP.

The dad joke
What do you get when you cross a website address with Chinese noodles? Chicken Domain.
Like this card?
Play the game

References

Answer: 53. DNS answers name lookups on port 53. Port 67 is the DHCP server and 80 is plain HTTP. Port 53 is used over both UDP and TCP.

  1. IANA Service Name and Transport Protocol Port Number Registry CSV www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
    domain,53,tcp,Domain Name Server
    Checked 2026-10-11.
  2. IANA Service Name and Transport Protocol Port Number Registry CSV www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
    domain,53,udp,Domain Name Server
    Checked 2026-10-11.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Tech & GadgetsWhich TCP port does Secure Shell (SSH) use by default?Tech & GadgetsWhich port does SMTP use by default to send and relay email?Tech & GadgetsWhich port does POP3 use by default to download email?

That's stuff everyone should know.