TCP/UDP ports used by Exchange 2000 Server

For purposes of configuring firewalls or for troubleshooting communications issues, it may be useful to know what TCP/UDP ports Exchange 2000 Server and Exchange 2000 Conferencing Server are using. This article offers a brief summary of the most common ports, protocols, and services used. The list is not guaranteed to be complete.

• Protocol: LDAP
  Port (TCP/UDP): 389 (TCP)
  Description: Lightweight Directory Access Protocol (LDAP), used by Active Directory, Active Directory Connector, and the Microsoft Exchange Server 5.5 directory.
• Protocol: LDAP/SSL
  Port (TCP/UDP): 636 (TCP)
  Description: LDAP over Secure Sockets Layer (SSL). When SSL is enabled, LDAP data that is transmitted and received is encrypted. To enable SSL, you must install a Computer certificate on the domain controller or Exchange Server 5.5 computer.
• Protocol: LDAP
  Port (TCP/UDP): 379 (TCP)
  Description: The Site Replication Service (SRS) uses TCP port 379.
• Protocol: LDAP
  Port (TCP/UDP): 390 (TCP)
  Description: While not a standard LDAP port, TCP port 390 is the recommended alternate port to configure the Exchange Server 5.5 LDAP protocol when Exchange Server 5.5 is running on a Microsoft Windows 2000 Active Directory domain controller.
• Protocol: LDAP
  Port (TCP/UDP): 3268 (TCP)
  Description: Global catalog. The Windows 2000 Active Directory global catalog (which is really a domain controller "role") listens on TCP port 3268. When you are troubleshooting issues that may be related to a global catalog, connect to port 3268 in LDP.
• Protocol: LDAP/SSL
  Port (TCP/UDP): 3269 (TCP)
  Description: Global catalog over SSL. Applications that connect to TCP port 3269 of a global catalog server can transmit and receive SSL encrypted data. To configure a global catalog to support SSL, you must install a Computer certificate on the global catalog.
• Protocol: IMAP4
  Port (TCP/UDP): 143 (TCP)
  Description: Internet Message Access Protocol version 4, may be used by "standards-based" clients such as Microsoft Outlook Express or Netscape Communicator to access the e-mail server. IMAP4 runs on top of the Microsoft Internet Information Service (IIS) Admin Service (Inetinfo.exe), and enables client access to the Exchange 2000 information store.
• Protocol: IMAP4/SSL
  Port (TCP/UDP): 993 (TCP)
  Description: IMAP4 over SSL uses TCP port 993. Before an Exchange 2000 server supports IMAP4 (or any other protocol) over SSL, you must install a Computer certificate on the Exchange 2000 server.
• Protocol: POP3
  Port (TCP/UDP): 110 (TCP)
  Description: Post Office Protocol version 3, enables "standards-based" clients such as Outlook Express or Netscape Communicator to access the e-mail server. As with IMAP4, POP3 runs on top of the IIS Admin Service, and enables client access to the Exchange 2000 information store.
• Protocol: POP3/SSL
  Port (TCP/UDP): 995 (TCP)
  Description: POP3 over SSL. To enable POP3 over SSL, you must install a Computer certificate on the Exchange 2000 server.
• Protocol: NNTP
  Port (TCP/UDP): 119 (TCP)
  Description: Network News Transport Protocol, sometimes called Usenet protocol, enables "standards-based" client access to public folders in the information store. As with IMAP4 and POP3, NNTP is dependent on the IIS Admin Service.
• Protocol: NNTP/SSL
  Port (TCP/UDP): 563 (TCP)
  Description: NNTP over SSL. To enable NNTP over SSL, you must install a Computer certificate on the Exchange 2000 Server.
• Protocol: HTTP
  Port (TCP/UDP): 80 (TCP)
  Description: Hyper-Text Transfer Protocol is the protocol used primarily by Microsoft Outlook Web Access (OWA), but also enables some administrative actions in Exchange System Manager. HTTP is implemented through the World Wide Web Publishing Service (W3Svc), and runs on top of the IIS Admin Service.
• Protocol: HTTP/SSL
  Port (TCP/UDP): 443 (TCP)
  Description: HTTP over SSL. To enable HTTP over SSL, you must install a Computer certificate on the Exchange 2000 server.
• Protocol: SMTP
  Port (TCP/UDP): 25 (TCP)
  Description: Simple Mail Transfer Protocol, is the foundation for all e-mail transport in Exchange 2000. The SMTP Service (SMTPSvc) runs on top of the IIS Admin Service. Unlike IMAP4, POP3, NNTP, and HTTP, SMTP in Exchange 2000 does not use a separate port for secure communication (SSL), but rather, employs an "in-band security sub-system" called Transport Layer Security (TLS).
• Protocol: SMTP/SSL
  Port (TCP/UDP): 465 (TCP)
  Description: SMTP over SSL. TCP port 465 is reserved by common industry practice for secure SMTP communication using the SSL protocol. However, unlike IMAP4, POP3, NNTP, and HTTP, SMTP in Exchange 2000 does not use a separate port for secure communication (SSL), but rather, employs an "in-band security sub-system" called Transport Layer Security (TLS). To enable TLS to work on Exchange 2000, you must install a Computer certificate on the Exchange 2000 server.
• Protocol: SMTP/LSA
  Port (TCP/UDP): 691 (TCP)
  Description: The Microsoft Exchange Routing Engine (also known as RESvc) listens for routing link state information on TCP port 691. Exchange 2000 uses routing link state information to route messages and the routing table is regularly updated. The Link State Algorithm (LSA) propagates outing status information between Exchange 2000 servers. This algorithm is based on the Open Shortest Path First (OSPF) protocol from networking technology, and transfers link state information between routing groups by using the X-LSA-2 command verb over SMTP and by using a Transmission Control Protocol (TCP) connection to port 691 in a routing group. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
  260995 Definitions of key transport components in Exchange 2000 Server
• Protocol: RVP
  Port (TCP/UDP): 80 (TCP)
  Description: RVP is the foundation for Instant Messaging in Exchange 2000. While RVP communication begins with TCP port 80, the server quickly sets up a new connection to the client on an ephemeral TCP port above 1024. Because this port is not known in advance, issues exist when you enable Instant Messaging through a firewall.
• Protocol: IRC/IRCX
  Port (TCP/UDP): 6667 (TCP)
  Description: Internet Relay Chat (IRC) is the chat protocol. IRCX is the extended version offered by Microsoft. While TCP port 6667 is the most common port for IRC, TCP port 7000 is also very frequently used.
• Protocol: IRC/SSL
  Port (TCP/UDP): 994 (TCP)
  Description: IRC (or Chat) over SSL. IRC or IRCX over SSL is not supported in Exchange 2000.
• Protocol: X.400
  Port (TCP/UDP): 102 (TCP)
  Description: ITU-T Recommendation X.400 is really a series of recommendations for what an electronic message handling system (MHS) should look like. TCP port 102 is defined in IETF RFC-1006, which describes OSI communications over a TCP/IP network. In brief, TCP port 102 is the port that the Exchange message transfer agent (MTA) uses to communicate with other X.400-capable MTAs.
• Protocol: MS-RPC
  Port (TCP/UDP): 135 (TCP)
  Description: Microsoft Remote Procedure Call is a Microsoft implementation of remote procedure calls (RPCs). TCP port 135 is actually only the RPC Locator Service, which is like the registrar for all RPC-enabled services that run on a particular server. In Exchange 2000, the Routing Group Connector uses RPC instead of SMTP when the target bridgehead server is running Exchange 5.5. Also, some administrative operations require RPC. To configure a firewall to enable RPC traffic, many more ports than just 135 must be enabled.
• Protocol: T.120
  Port (TCP/UDP): 1503 (TCP)
  Description: ITU-T Recommendation T.120 is a series of recommendations that define data conferencing. Data conferencing is implemented on the server side as a Conferencing Technology Provider (CTP) in the Multipoint Control Unit (MCU), which is one component of the Exchange Conferencing Services (ECS). Data conferencing is implemented on the client side as Chat, Application Sharing, Whiteboard, and File Transferring in Microsoft NetMeeting.
• Protocol: ULS
  Port (TCP/UDP): 522 (TCP)
  Description: User Locator Service is a type of Internet directory service for conferencing clients, such as NetMeeting. Exchange 2000 Server and Exchange 2000 Conferencing Server do not implement a ULS, but rather take advantage of Active Directory for directory services (by TCP port 389).
• Protocol: H.323 (Video)
  Port (TCP/UDP): 1720 (TCP)
  Description: ITU-T Recommendation H.323 defines multimedia conferencing. TCP port 1720 is the H.323 (video) call setup port. After a client connects, the H.323 server negotiates a new, dynamic UDP port to be used for streaming data.
  
  
  161931 Configuring MTA TCP/IP port # for X.400 and RPC listens
  H.323 Video Conferencing is implemented on the server side as a CTP on the MCU in ECS. On the client side, it is implemented as Video in NetMeeting.
• Protocol: Audio
  Port (TCP/UDP): 1731 (TCP)
  Description: Audio conferencing is enabled in much the same way as H.323 video conferencing is enabled in Exchange 2000 Server. After clients connect to TCP port 1731, a new dynamic port is negotiated for further streaming data.
• Protocol: DNS
  Port (TCP/UDP): 53 (TCP)
  Description: Domain Name System (DNS) is at the heart of all of the services and functions of Windows 2000 Active Directory and Exchange 2000 Server. You cannot underestimate the impact that a DNS issue can have on the system. Therefore, when service issues arise, it is always good to verify proper name resolution.