Port 631Internet Printing Protocol

The Internet Printing Protocol (IPP) is a network protocol used for distributed printing over IP networks. It allows clients to submit print jobs to networked printers, query printer capabilities, manage print jobs, and receive status updates, making it a widely adopted standard for modern network printing solutions..

transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
4/10

caution

lookups
9,992

rank 469 of 993 · top 47%

1 other service is registered on port 631. compare all 2

Technical Details

what runs on :631

The Internet Printing Protocol (IPP) is an advanced network printing protocol designed to support the transmission of print jobs and the management of printing services over IP-based networks. IPP builds upon the Hypertext Transfer Protocol (HTTP), leveraging its request-response model and security capabilities for reliable and extensible communication. It supports functionalities such as print job submission, job status monitoring, job manipulation (pause, cancel, restart), and querying printer capabilities.

One of the key advantages of IPP is its platform and device independence, supported by a standardized schema and MIME media types for diverse document formats. IPP enables seamless integration into heterogeneous network environments, making it suitable for use in small offices, large enterprises, and within cloud printing infrastructures. The protocol versions, such as IPP 1.1 and IPP Everywhere, have introduced additional features including automatic discovery, driverless printing, and improved security options.

IPP typically operates over TCP and UDP port 631, using HTTP encapsulation to facilitate integration with existing web infrastructure and security protocols like TLS. Its compatibility with modern networking standards has contributed to its widespread adoption as the default printing protocol in many operating systems and network printer devices.

Security Information

exposure of :631

risk score

4/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

network services averages 3.9 across 604 ports — this one sits 0.1 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

Common Vulnerabilities:

  • IPP implementations may be exposed to unauthorized access if exposed on open or unprotected networks, potentially allowing attackers to intercept or manipulate print jobs.
  • Insufficient authentication mechanisms can lead to abuse, such as unauthorized usage, denial of service, or data leakage via printed documents.
  • If IPP runs without encryption, it is susceptible to man-in-the-middle attacks, data interception, or session hijacking.
  • Exploitable vulnerabilities in printer firmware or IPP services can be leveraged to execute arbitrary code or gain network footholds.

Common Mitigations:

  • Always enable encryption (e.g., IPP over HTTPS) to protect data in transit between clients and printers.
  • Restrict IPP access using network segmentation, firewalls, and access control lists to trusted devices and subnets.
  • Enforce strong authentication and authorization to prevent unauthorized print job submission and management.
  • Regularly update printer firmware and monitor vendor advisories to patch known vulnerabilities.
  • Disable unused protocols or services on printers to reduce attack surface and exposure.

the 8 most looked-up other ports in network services — 604 ports carry that label.

risk mix of the 8 listed

  • caution100%

0 of 8 encrypted