Port 71NETRJS Remote Job

Port 71 is historically used for the NETRJS (Remote Job Service), primarily designed to facilitate remote job entry and processing on mainframe systems. It allowed users to submit, manage, and receive output from batch processing jobs remotely over a network connection..

transport
tcp

single transport

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
4/10

caution

lookups
6,694

rank 764 of 993 · top 77%

Technical Details

what runs on :71

Port 71 is associated with the NETRJS - Remote Job Service protocol developed during the era of mainframe computing. It was primarily employed in IBM mainframes and related systems, enabling remote terminals or client systems to submit batch processing tasks to centralized computing resources. This streamlined workflows by decoupling job scheduling and resource use from physical presence.

Functionally, NETRJS operated over TCP, creating a reliable connection between a client terminal and the mainframe service. Users could upload job control language (JCL) files, receive printouts, and manage job execution status through a standardized interface. This facilitated efficient workload management, especially in large organizations that relied heavily on mainframe batch processing.

While modern enterprise IT has largely transitioned away from such protocols to more streamlined management tools and APIs, the NETRJS service remains a part of legacy network protocol documentation. Usage today is rare, and often exists only in niche environments or in emulations of older systems.

Security Information

exposure of :71

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

every listening transport is another surface to filter at the edge

security overview

Common security vulnerabilities regarding port 71 include:

  • Lack of encryption, leading to potential interception and monitoring of sensitive data transferred between client and mainframe.
  • Weak or absent authentication mechanisms, increasing the risk of unauthorized access.
  • Susceptibility to denial of service (DoS) attacks if the service is inadvertently exposed to untrusted networks.

Common mitigations include:

  • Closing or disabling port 71 entirely if the service is not explicitly required.
  • Implementing strict network segmentation and firewall policies to limit access.
  • Using secure alternatives and encrypted communication channels to replace legacy remote job entry workflows.
  • Monitoring network activity for unusual or unauthorized use of this port.

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