Firewall Ports for Active Directory Domain Join

By EssingtonITS team ·

The article outlines the essential and optional firewall ports needed for joining an Active Directory domain, including TCP 88 for Kerberos and TCP 135 for RPC. It highlights the importance of opening high TCP ports to avoid RPC server errors.

Firewall Ports Required to Join an AD Domain (Minimum)

  • TCP 88 (Kerberos Key Distribution Centre)
  • TCP 135 (Remote Procedure Call)
  • TCP 139 (NetBIOS Session Service)
  • TCP 389 (LDAP)
  • TCP 445 (SMB, Net Logon)
  • UDP 53 (DNS)
  • UDP 389 (LDAP, DC Locator, Net Logon)
  • TCP 49152-65535 (Randomly allocated high TCP ports)

It's crucial to ensure the TCP high ports are open. If they're not, you might run into errors about unavailable RPC servers, which can be a real headache when you're trying to join the domain.

Optional Ports

  • UDP 123 (NTP)
  • TCP 53 (DNS)
  • TCP 464 (Kerberos Password V5 – Used when users change their password from their desktop)
  • UDP 137 (NetBIOS Name Resolution)
  • UDP 138 (NetBIOS Datagram Service)
  • TCP 636 (LDAP SSL)
  • UDP 636 (LDAP SSL)
  • TCP 3268 (Global Catalogue)

Looking to enhance your Linux infrastructure? At EssingtonITS.co.uk, we offer expert support and tailored solutions to optimise your systems. Let us help you achieve seamless integration and improved performance.

person people found this useful.

Related

Knowledge base 16 Oct 2026

Building a Windows 11 gold template

Learn how to create a Windows 11 gold template in Proxmox for VDI environments, allowing for efficient desktop pool management. This guide is aimed at engineers and includes steps for setting up, configuring, and testing the template.

Knowledge base 10 Oct 2026

eLLA - Settings, Options and Skills Reference

eLLA is a command-line assistant for system administration. It connects to an eLLM endpoint (any OpenAI-compatible API with tool calling), runs read-only diagnostics on its own, and asks for approval before it changes anything. This article lists every setting, command, option and bundled skill.

Knowledge base 23 Sep 2026

eSAM and exam regulations

eSAM addresses every requirement in JCQ Appendix 1 that software can address. The rest, who is sitting there, how the room is laid out, how many invigilators are watching stay with the centre, and eSAM tells you exactly which those are.

Expand 29 Jul 2026

How AI can support pupils with SEND

Explore how AI tools are aiding pupils with special educational needs and disabilities by simplifying text, breaking down tasks, and enhancing accessibility. Learn about the considerations schools should make before implementation.

Expand 29 Jul 2026

AI policy and practice in further education

Further education colleges need distinct AI policies due to their unique mix of vocational courses, diverse age groups, and specific funding and inspection requirements. This guidance highlights the importance of tailored AI approaches in FE settings.