Technical Web Log

Source: http://www.windowsnetworking.com/kbase/WindowsTips/WindowsServer2008/AdminTips/ActiveDirectory/WhatAllPortsAreRrequiredByDomainControllersAndClientComputers.html This article explains the key port requirement for Client computers and Domain Controllers communicating with each other. Active Directory communication takes place using several ports. These ports are required by both client computers and Domain Controllers. As an example, when a client computer tries to find a domain controller it always sends a DNS Query over Port 53 to find the name of the domain controller in the domain. The following is the list of services and their ports used for Active Directory communication: UDP Port 88 for Kerberos authentication UDP and TCP Port 135 for domain controllers-to-domain controller and client to domain controller operations. TCP Port 139 and UDP 138 for File Replication Service between domain controllers. UDP Port 389 for LDAP to handle normal queries from client...