Port 631 — IPP / CUPS
Quick reference for TCP/UDP port 631, used by IPP / CUPS. Includes what the service does, security guidance and related ports.
What is port 631?
Internet Printing Protocol; used by macOS/Linux print servers.
What port does IPP / CUPS use?
IPP / CUPS listens on port 631 by default.
Security guidance
Medium risk — open with care
Port 631 (IPP / CUPS) can safely face the internet if you keep the software up to date, restrict admin endpoints, and use TLS where possible. Audit who can reach it and watch your logs.
Related ports
Frequently asked
What is port 631 used for?+
Port 631 is the standard TCP/UDP port for IPP / CUPS. Internet Printing Protocol; used by macOS/Linux print servers.
What port does IPP / CUPS use?+
IPP / CUPS listens on port 631 by default.
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