udp port assignment

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Understanding TCP/UDP Client Port Assignment

Not sure how else to phrase the question so that's why it's phrased the way it is. I have these two questions:

• Is it possible for two TCP segments with source port 80 to be sent by different processes at the sending host
• Is it possible for two UDP segments with source port 5723 to be sent by different processes at the same host?

I was unsure of the answer at first, but I believe the answer for both of these to be no, it isn't possible. The reason for this is in the case of TCP, there is no way to uniquely identify the segment because the 4 tuple (source port, dest port, source ip, and dest ip) will be the same across both processes which means no way to distinguish between the segments. Similarly, for UDP, the IP datagram will carry the source/dest IP, however, these will be the same. The UDP segment will carry the source port/dest port, but again, these will be the same. This means no ability to distinguish between segments for either protocol.

Possible solutions are to use the processes on two separate clients (would mean separate IP, solving the problem in both scenarios), or using the processes from the same host with different ports.

Please inform me if this is correct or if I'm way off, please tell me why. Thank you for your time!

• network-programming

• First, neither TCP nor UDP have clients or servers. Client/server is an application concept. Next, port numbers for TCP and UDP are really addresses for the process attached to the transport protocol. The port numbers are per protocol, so TCP 12345 is not TCP 12345. A process attached to a port number of either protocol exclusively uses that port number for that protocol. –  Ron Maupin Commented Oct 5, 2020 at 1:33

There's a related question: TCP: can two different sockets share a port? This piece is relevant there:

a given socket connection is uniquely identified by a combination of transport protocol, client IP+port, and server IP+port. Multiple clients can connect to the same server IP+port only if their client IP+port are different from each other

So I think you're mostly right but there can be special circumstances caused by SO_REUSEADDR or SO_REUSEPORT which might allow multiple different processes to reuse the same port: TCP - possible for same client-side port to be used for different connections by different applications simlutaneously?

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Service overview and network port requirements for Windows

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This article discusses the required network ports, protocols, and services that are used by Microsoft client and server operating systems, server-based programs, and their subcomponents in the Microsoft Windows Server system. Administrators and support professionals may use this article as a roadmap to determine which ports and protocols Microsoft operating systems and programs require for network connectivity in a segmented network.

Original KB number:   832017

This article contains several references to the default dynamic port range. In Windows Server 2008 and later versions, and in Windows Vista and later versions, the default dynamic port range changed to the following range:

• Start port: 49152
• End port: 65535

Windows 2000, Windows XP, and Windows Server 2003 use the following dynamic port range:

• Start port: 1025
• End port: 5000

What this means for you:

• If your computer network environment uses only Windows Server 2012 or a later version of Windows, you must enable connectivity over the high port range of 49152 through 65535.
• If your computer network environment uses Windows Server 2012 together with versions of Windows earlier than Windows Server 2008 and Windows Vista, you must enable connectivity over both the following port ranges: High port range 49152 through 65535 Low port range 1025 through 5000

If your computer network environment uses only versions of Windows earlier than Windows Server 2008 and Windows Vista, you must enable connectivity over the low port range of 1025 through 5000.

For more information about the default dynamic port range, see The default dynamic port range for TCP/IP has changed .

Don't use the port information in this article to configure Windows Firewall. For information about how to configure Windows Firewall, see Windows Firewall with Advanced Security .

The Windows Server system includes a comprehensive and integrated infrastructure to meet the requirements of developers and information technology (IT) professionals. This system runs programs and solutions that you can use to obtain, analyze, and share information quickly and easily. These Microsoft client, server, and server program products use different network ports and protocols to communicate with client systems and with other server systems over the network. Dedicated firewalls, host-based firewalls, and Internet Protocol security (IPsec) filters are other important components that you must have to help secure your network. However, if these technologies are configured to block ports and protocols that are used by a specific server, that server will no longer respond to client requests.

The following list provides an overview of the information that this article contains:

The System services ports section:

• Contains a brief description of each service.
• Displays the logical name of each service.
• Indicates the ports and protocols that each service requires for correct operation.

Use this section to help identify the ports and protocols that a particular service uses.

The Ports and protocols section includes a table that summarizes the information from the System services ports section. The table is sorted by the port number instead of by the service name. Use this section to quickly determine which services listen on a particular port.

This article uses certain terms in specific ways. To help avoid confusion, make sure that you understand how the article uses these terms:

• System services: System services are programs that load automatically as part of an application's startup process or as part of the operating system startup process. System services support the different tasks that the operating system must perform. For example, some system services that are available on computers that run Windows Server 2003 Enterprise Edition include the Server service, the Print Spooler service, and the World Wide Web Publishing service. Each system service has a friendly service name and a service name . The friendly service name is the name that appears in graphical management tools such as the Services Microsoft Management Console (MMC) snap-in. The service name is the name that is used with command-line tools and with many scripting languages. Each system service may provide one or more network services.
• Application protocol: In this article, application protocol refers to a high-level network protocol that uses one or more TCP/IP protocols and ports. Examples of application protocols include HTTP, server message blocks (SMBs), and Simple Mail Transfer Protocol (SMTP).
• Protocol: TCP/IP protocols are standard formats for communicating between devices on a network. TCP/IP protocols operate at a lower level than the application protocols. The TCP/IP suite of protocols includes TCP, User Datagram Protocol (UDP), and Internet Control Message Protocol (ICMP).
• Port: It's the network port that the system service listens on for incoming network traffic.

This article doesn't specify which services rely on other services for network communication. For example, many services rely on the Remote Procedure Call (RPC) or DCOM features in Microsoft Windows to assign them dynamic TCP ports. The Remote Procedure Call service coordinates requests by other system services that use RPC or DCOM to communicate with client computers. Many other services rely on network basic input/output system (NetBIOS) or SMBs, protocols that are provided by the Server service. Other services rely on HTTP or on Hypertext Transfer Protocol Secure (HTTPS). These protocols are provided by Internet Information Services (IIS). A full discussion of the architecture of the Windows operating systems is beyond the scope of this article. However, detailed documentation on this subject is available on Microsoft TechNet and on the Microsoft Developer Network (MSDN) websites. Although many services may rely on a particular TCP or UDP port, only one service or process at a time can listen on that port.

When you use RPC with TCP/IP or with UDP/IP as the transport, incoming ports are frequently dynamically assigned to system services as required. TCP/IP and UDP/IP ports that are higher than port 1024 are used. These ports are also informally known as random RPC ports . In these cases, RPC clients rely on the RPC endpoint mapper to tell them which dynamic port or ports were assigned to the server. For some RPC-based services, you can configure a specific port instead of letting RPC dynamically assign a port. You can also restrict the range of ports that RPC dynamically assigns to a small range, regardless of the service. For more information about this topic, see the References section.

This article includes information about the system services roles and the server roles for the Microsoft products that are listed in the Applies to section. Although this information may also apply to Windows XP and to Microsoft Windows 2000 Professional, this article is focused on server-class operating systems. Therefore, this article describes the ports that a service listens on instead of the ports that client programs use to connect to a remote system.

System services ports

This section provides a description of each system service, includes the logical name that corresponds to the system service, and displays the ports and the protocols that each service requires.

Active Directory (local security authority)

Active Directory runs under the Lsass.exe process and includes the authentication and replication engines for Windows domain controllers. Domain controllers, client computers, and application servers require network connectivity to Active Directory over specific hard-coded ports. Additionally, unless a tunneling protocol is used to encapsulate traffic to Active Directory, a range of ephemeral TCP ports between 1024 to 5000 and 49152 to 65535 are required.

If your computer network environment uses only Windows Server 2008 R2, Windows Server 2008, Windows 7, Windows Vista or later versions, you must enable connectivity over the high port range of 49152 through 65535.

If your computer network environment uses Windows Server 2008 R2, Windows Server 2008, Windows 7, Windows Vista or later versions together with versions of Windows earlier than Windows Server 2008 and Windows Vista, you must enable connectivity over both port ranges: High port range of 49152 through 65535 Low port range of 1025 through 5000

An encapsulated solution might consist of a VPN gateway located behind a filtering router that uses Layer 2 Tunneling Protocol (L2TP) together with IPsec. In this encapsulated scenario, you must allow the following items through the router instead of opening all the ports and protocols listed in this topic:

• IPsec Encapsulating Security Protocol (ESP) (IP protocol 50)
• IPsec Network Address Translator Traversal NAT-T (UDP port 4500)
• IPsec Internet Security Association and Key Management Protocol (ISAKMP) (UDP port 500)

Finally, you can hard-code the port that is used for Active Directory replication by following the steps in Restricting Active Directory RPC traffic to a specific port . System service name: LSASS .

Packet filters for L2TP traffic are not required, because L2TP is protected by IPsec ESP.

¹ For more information about how to customize this port, see Domain controllers and Active Directory in the References section. This section also includes remote WMI and DCOM communications first used in Windows Server 2012 domain controller promotion during prerequisite validation and with the Server Manager tool.

In addition, the Microsoft LDAP client uses ICMP pings to verify that an LDAP server it has a pending request with is still present on the network. The following settings are LDAP session options:

• PingKeepAliveTimeout = 120 seconds (how long it waits after last response from server before it starts sending ping)
• PingLimit = 4 (how many pings are sent before connection is closed)
• PingWaitTimeout = 2000 ms (how long it waits for the ICMP response)
• Reference: LdapSessionOptions Class

Application Layer Gateway service

This subcomponent of the Internet Connection Sharing/Internet Connection Firewall (ICF) service provides support for plug-ins that allow network protocols to pass through the firewall and work behind Internet Connection Sharing. Application Layer Gateway (ALG) plug-ins can open ports and change data (such as ports and IP addresses) that are embedded in packets. FTP is the only network protocol that has a plug-in that is included with Windows Server. The ALG FTP plug-in supports active FTP sessions through the network address translation (NAT) engine that these components use. The ALG FTP plug-in supports these sessions by redirecting all traffic that meets the following criteria to a private listening port in the range of 3000 to 5000 on the loopback adapter:

• Passes through the NAT engine
• Is directed toward port 21

The ALG FTP plug-in then monitors and updates FTP control channel traffic so that the FTP plug-in can forward port mappings through the NAT for the FTP data channels. The FTP plug-in also updates ports in the FTP control channel stream.

System service name: ALG

ASP.NET State Service

ASP.NET State Service provides support for ASP.NET out-of-process session states. ASP.NET State Service stores session data out-of-process. The service uses sockets to communicate with ASP.NET that is running on a web server.

System service name: aspnet_state

Certificate Services

Certificate Services is part of the core operating system. By using Certificate Services, a business can act as its own certification authority (CA). It lets the business issue and manage digital certificates for programs and protocols such as:

• Secure/Multipurpose Internet Mail Extensions (S/MIME)
• Secure Sockets Layer (SSL)
• Encrypting File System (EFS)
• Smart card logon

Certificate Services relies on RPC and DCOM to communicate with clients by using random TCP ports that are higher than port 1024.

System service name: CertSvc

¹ For more information about how to customize this port, see Remote Procedure Calls and DCOM in the References section.

For more information, see 3.2.2.6.2.1.4.5.9 msPKI-Certificate-Name-Flag .

Cluster service

The Cluster service controls server cluster operations and manages the cluster database. A cluster is a collection of independent computers that act as a single computer. Managers, programmers, and users see the cluster as a single system. The software distributes data among the nodes of the cluster. If a node fails, other nodes provide the services and data that were formerly provided by the missing node. When a node is added or repaired, the cluster software migrates some data to that node.

System service name: ClusSvc

Additionally, for successful validation on Windows Failover Clusters on 2008 and above, allow inbound and outbound traffic for ICMP4, ICMP6, and port 445/TCP for SMB.

¹ Cluster Service UDP traffic over port 3343 requires the Datagram Transport Layer Security (DTLS) protocol, version 1.0 or version 1.2. By default, DTLS is enabled. For more information, see Protocols in TLS/SSL (Schannel SSP) .

² For more information about how to customize these ports, see Remote Procedure Calls and DCOM in the References section.

• Computer Browser

The Computer Browser system service maintains an up-to-date list of computers on your network and supplies the list to programs that request it. The Computer Browser service is used by Windows-based computers to view network domains and resources. Computers that are designated as browsers maintain browse lists that contain all shared resources that are used on the network. Earlier versions of Windows-based programs, such as My Network Places, the net view command, and Windows Explorer, all require browsing capability. For example, when you open My Network Places on a computer that is running Microsoft Windows 95, a list of domains and computers appears. To display this list, the computer obtains a copy of the browse list from a computer that is designated as a browser.

If you are running only Windows Vista and later versions of Windows, the browser service is no longer required.

System service name: Browser

The Browser service uses RPC over Named Pipes to compile.

Dynamic Host Configuration Protocol (DHCP) Server

The DHCP Server service uses the DHCP to automatically allocate IP addresses. You can use this service to adjust the advanced network settings of DHCP clients. For example, you can configure network settings such as Domain Name System (DNS) servers and Windows Internet Name Service (WINS) servers. You can establish one or more DHCP servers to maintain TCP/IP configuration information and to provide that information to client computers.

System service name: DHCPServer

• Distributed File System Namespaces

The Distributed File System Namespaces (DFSN) integrates different file shares that are located on a local area network (LAN) or wide area network (WAN) into a single logical namespace. The DFSN service is required for Active Directory domain controllers to advertise the SYSVOL shared folder.

System service name: Dfs

2 The NETBIOS ports are optional and are not required when DFSN is using FQDN Server names.

• Distributed File System Replication

The Distributed File System Replication (DFSR) service is a state-based, multi-master file replication engine that automatically copies updates to files and folders between computers that are participating in a common replication group. DFSR was added in Windows Server 2003 R2. You can configure DFSR by using the Dfsrdiag.exe command-line tool to replicate files on specific ports, regardless of whether they are participating in Distributed File System Namespaces (DFSN).

System service name: DFSR

¹ For more information about how to customize this port, see Distributed File Replication Service in the References section.

2 Port 5722 is only used on a Windows Server 2008 domain controller or on a Windows Server 2008 R2 domain controller. It is not used on a Windows Server 2012 domain controller.

• Distributed Link Tracking Server

The Distributed Link Tracking Server system service stores information so that files that are moved between volumes can be tracked to each volume in the domain. The Distributed Link Tracking Server service runs on each domain controller in a domain. This service enables the Distributed Link Tracking Client service to track linked documents that are moved to a location in another NTFS file system volume in the same domain.

System service name: TrkSvr

• Distributed Transaction Coordinator

The Distributed Transaction Coordinator (DTC) system service coordinates transactions that are distributed across multiple computer systems and resource managers, such as databases, message queues, file systems, or other transaction-protected resource managers. The DTC system service is required if transactional components are configured through Component Object Model Plus (COM+). It's also required for transactional queues in Message Queuing (also known as MSMQ) and SQL Server operations that span multiple systems.

System service name: MSDTC

¹ For more information about how to customize this port, see Distributed Transaction Coordinator in the References section.

The DNS Server service enables DNS name resolution by answering queries and update requests for DNS names. DNS servers are required to locate devices and services that are identified by using DNS names and to locate domain controllers in Active Directory.

System service name: DNS

The Event Log system service logs event messages that are generated by programs and by the Windows operating system. Event log reports contain information that you can use to diagnose problems. You view reports in Event Viewer. The Event Log service writes events that are sent to log files by programs, by services, and by the operating system. The events contain diagnostic information in addition to errors that are specific to the source program, the service, or the component. The logs can be viewed programmatically through the event log APIs or through the Event Viewer in an MMC snap-in.

System service name: Eventlog

The Event Log service uses RPC over named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.

• Fax Service

Fax Service, a Telephony API (TAPI) compliant system service, provides fax capabilities. Fax Service lets users use either a local fax device or a shared network fax device to send and receive faxes from their desktop programs.

System service name: Fax

File Replication

The File Replication service (FRS) is a file-based replication engine that automatically copies updates to files and folders between computers that are participating in a common FRS replica set. FRS is the default replication engine that is used to replicate the contents of the SYSVOL folder between Windows 2000-based domain controllers and Windows Server 2003-based domain controllers that are located in a common domain. You can use the DFS Administration tool to configure FRS to replicate files and folders between targets of a DFS root or link.

System service name: NtFrs

¹ For more information about how to customize this port, see File Replication Service in the References section.

FTP Publishing Service

FTP Publishing Service provides FTP connectivity. By default, the FTP control port is 21. However, you can configure this system service through the Internet Information Services (IIS) Manager snap-in. The default data (that is used for active mode FTP) port is automatically set to one port less than the control port. Therefore, if you configure the control port to port 4131, the default data port is port 4130. Most FTP clients use passive mode FTP. This means that the client first connects to the FTP server by using the control port. Next, the FTP server assigns a high TCP port between ports 1025 and 5000. Then, the client opens a second connection to the FTP server for transferring data. You can configure the range of high ports by using the IIS metabase.

System service name: MSFTPSVC

Group Policy

To successfully apply Group Policy, a client computer must be able to contact a domain controller over the Kerberos, LDAP, SMB, and RPC protocols. Windows XP and Windows Server 2003 additionally require the ICMP protocol.

If any one of these protocols is unavailable or blocked between the client and a relevant domain controller, Group Policy will not apply or update. For a cross-domain logon, where a computer is in one domain and the user account is in another domain, these protocols may be required for the client, the resource domain, and the account domain to communicate. ICMP is used for slow link detection.

System service name: Group Policy

¹ For more information about how to customize this port, see Domain controllers and Active Directory in the References section.

2 This protocol is required only by Windows XP and Windows Server 2003 acting as clients.

When the Group Policy Microsoft Management Console (MMC) snap-in creates Group Policy Results reports and Group Policy Modeling reports, it uses DCOM and RPC to send and to receive information from the Resultant Set of Policy (RSoP) provider on the client or on the domain controller. The various binary files that make up the Group Policy Microsoft Management Console (MMC) snap-in features primarily use COM calls to send or to receive information. When you initiate remote group policy results reporting from a Windows Server 2012 computer, access to the destination computer's event log is required. (See the Event Log section in this article for port requirements.)

Windows Server 2012 support the initiation of remote group policy update against Windows Server 2012 computers. This requires RPC/WMI access through port 135 and ports 49152-65535 inbound to the computer on which the policy is being refreshed.

The HTTP SSL system service enables IIS to perform SSL functions. SSL is an open standard for establishing an encrypted communications channel to help prevent the interception of extremely important information, such as credit card numbers. Although this service works on other Internet services, it is primarily used to enable encrypted electronic financial transactions on the World Wide Web (WWW). You can configure the ports for this service through the Internet Information Services (IIS) Manager snap-in.

System service name: HTTPFilter

Hyper-V service

Hyper-V replica

Hyper-V live migration

• Internet Authentication Service

Internet Authentication Service (IAS) performs centralized authentication, authorization, auditing, and accounting of users who are connecting to a network. These users can be on a LAN connection or on a remote connection. IAS implements the Internet Engineering Task Force (IETF) standard Remote Authentication Dial-In User Service (RADIUS) protocol.

System service name: IAS

Internet Connection Firewall (ICF)/Internet Connection Sharing

This system service provides NAT, addressing, and name resolution services for all computers on your home network or your small-office network. When the Internet Connection Sharing feature is enabled, your computer becomes an Internet gateway on the network. Other client computers can then share one connection to the Internet, such as a dial-up connection or a broadband connection. This service provides basic DHCP and DNS services but will work with the full-featured Windows DHCP or DNS services. When ICF and Internet Connection Sharing act as a gateway for the rest of the computers on your network, they provide DHCP and DNS services to the private network on the internal network interface. They do not provide these services on the external network interface.

System service name: SharedAccess

IP Address Management (IPAM)

The IPAM client UI communicates with the IPAM server to perform remote management. It's done by using the Windows Communications Framework (WCF), which uses TCP as the transport protocol. By default, the TCP binding is performed on port 48885 on the IPAM server.

BranchCache information

• Port 3702 (UDP) is used to discover the availability of cached content on a client.
• Port 80 (TCP) is used to serve content to requesting clients.
• Port 443 (TCP) is the default port that is used by the hosted cache to accept incoming client offers for content.

ISA/TMG Server

• This port is not used with ISA 2000.
• FWC application transport and protocols are negotiated within the FWC control channel.
• ISA 2000 FWC control uses UDP. ISA 2004 and 2006 use TCP.
• OEM uses Firewall Web Management to provide non-MMC management of ISA Server.
• This port is also used for intra-array traffic.
• This port is used only by the ISA management MMC during remote server and service status monitoring.
• It's the range in TMG. Please note that TMG extends the default dynamic port ranges in Windows Server 2008 R2, Windows 7, Windows Server 2008, and Windows Vista.
• Kerberos Key Distribution Center

When you use the Kerberos Key Distribution Center (KDC) system service, users can sign in to the network by using the Kerberos version 5 authentication protocol. As in other implementations of the Kerberos protocol, the KDC is a single process that provides two services: the Authentication Service and the Ticket-Granting Service. The Authentication Service issues ticket granting tickets, and the Ticket-Granting Service issues tickets for connection to computers in its own domain.

System service name: kdc

• License Logging

The License Logging system service is a tool that was originally designed to help customers manage licenses for Microsoft server products that are licensed in the server client access license (CAL) model. License Logging was introduced with Microsoft Windows NT Server 3.51. By default, the License Logging service is disabled in Windows Server 2003. Because of legacy design constraints and evolving license terms and conditions, License Logging may not provide an accurate view of the total number of CALs that are purchased compared to the total number of CALs that are used on a particular server or across the enterprise. The CALs that are reported by License Logging may conflict with the interpretation of the Microsoft Software License Terms and with Product Use Rights (PUR). License Logging is not included in Windows Server 2008 and later operating systems. We recommend that only users of the Microsoft Small Business Server family of operating systems enable this service on their servers.

System service name: LicenseService

The License Logging service uses RPC over named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.

Message Queuing

The Message Queuing system service is a messaging infrastructure and development tool for creating distributed messaging programs for Windows. These programs can communicate across heterogeneous networks and can send messages between computers that may be temporarily unable to connect to one another. Message Queuing helps provide security, efficient routing, support for sending messages within transactions, priority-based messaging, and guaranteed message delivery.

System service name: MSMQ

Microsoft Exchange Message Transfer Agent (MTA) stacks

In Microsoft Exchange 2000 Server and Exchange Server 2003, the MTA is frequently used to provide backward-compatible message transfer services between Exchange 2000 Server-based servers and Exchange Server 5.5-based servers in a mixed-mode environment.

System service name: MSExchangeMTA

Microsoft POP3 service

The Microsoft POP3 service provides email transfer and retrieval services. Administrators can use this service to store and manage email accounts on the mail server. When you install POP3 service on the mail server, users can connect to the mail server and can retrieve email messages by using an email client that supports the POP3 protocol, such as Microsoft Outlook.

System service name: POP3SVC

The Net Logon system service maintains a security channel between your computer and the domain controller to authenticate users and services. It passes the user's credentials to a domain controller and returns the domain security identifiers and the user rights for the user. This is typically known as pass-through authentication. Net Logon is configured to start automatically only when a member computer or domain controller is joined to a domain. In the Windows 2000 Server and Windows Server 2003 families, Net Logon publishes service resource locator records in the DNS. When this service runs, it relies on the WORKSTATION service and on the Local Security Authority service to listen for incoming requests. On domain member computers, Net Logon uses RPC over named pipes. On domain controllers, it uses RPC over named pipes, RPC over TCP/IP, mail slots, and Lightweight Directory Access Protocol (LDAP).

System service name: Netlogon

2 The NETBIOS ports are optional. Netlogon uses these only for trusts that don't support DNS or when DNS fails during an attempted fallback. If there is no WINS infrastructure and broadcasts can't work, you should either disable NetBt or set the computers and servers to NodeType=2.

The Net Logon service uses RPC over named pipes for earlier versions of Windows clients. This service has the same firewall requirements as the File and Printer Sharing feature.

Network News Transfer Protocol (NNTP)

The Network News Transfer Protocol (NNTP) system service lets computers that are running Windows Server 2003 act as news servers. Clients can use a news client, such as Microsoft Outlook Express, to retrieve newsgroups from the server and to read the headers or the bodies of the articles in each newsgroup.

System service name: NNTPSVC

Offline Files, User Profile Service, Folder Redirection, and Primary Computer

Offline Files and Roaming User Profiles cache user data to computers for offline use. These capabilities exist in all supported Microsoft operating systems. Windows XP implemented roaming user profile caching as part of the Winlogon process while Windows Vista, Windows Server 2008, and later operating systems use the User Profile Service. All of these systems use SMB.

Folder Redirection redirects user data from the local computer to a remote file share, using SMB.

The Primary Computer system for Windows is part of the Roaming User Profile and Offline Files services. Primary Computer provides a capability to prevent data caching to computers that are not authorized by administrators for specific users. Primary Computer uses LDAP to determine the configuration and does not perform any data transfer using SMB; it instead alters the default Offline Files and Roaming User Profile behaviors. This system was added in Windows Server 2012.

System service names: ProfSvc , CscService

Performance Logs and Alerts

The Performance Logs and Alerts system service collects performance data from local or remote computers based on preconfigured schedule parameters and then writes that data to a log or triggers a message. Based on the information that is contained in the named log collection setting, the Performance Logs and Alerts service starts and stops each named performance data collection. This service runs only if at least one performance data collection is scheduled.

System service name: SysmonLog

• Print Spooler

The Print Spooler system service manages all local and network print queues and controls all print jobs. Print Spooler is the center of the Windows printing subsystem. It manages the print queues on the system and communicates with printer drivers and input/output (I/O) components, such as the USB port and the TCP/IP protocol suite.

System service name: Spooler

The Print Spooler service uses RPC over named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.

• Remote Installation

You can use the Remote Installation system service to install Windows 2000, Windows XP, and Windows Server 2003 on Pre-Boot Execution Environment (PXE) remote boot-enabled client computers. The Boot Information Negotiation Layer (BINL) service, the primary component of Remote Installation Server (RIS), answers PXE client requests, checks Active Directory for client validation, and passes client information to and from the server. The BINL service is installed when you add the RIS component from Add/Remove Windows Components, or you can select it when you first install the operating system.

System service name: BINLSVC

• Remote Procedure Call (RPC)

The Remote Procedure Call (RPC) system service is an interprocess communication (IPC) mechanism that enables data exchange and invocation of functionality that is located in a different process. The different process can be on the same computer, on the LAN, or in a remote location, and it can be accessed over a WAN connection or over a VPN connection. The RPC service serves as the RPC Endpoint Mapper and Component Object Model (COM) Service Control Manager. Many services depend on the RPC service to start successfully.

System service name: RpcSs

• RPC does not use only the hard-coded ports that are listed in the table. Ephemeral range ports that are used by Active Directory and other components occur over RPC in the ephemeral port range. The ephemeral port range depends on the server operating system that the client operating system is connected to.
• The RPC Endpoint Mapper also offers its services by using named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.
• Remote Procedure Call (RPC) Locator

The Remote Procedure Call (RPC) Locator system service manages the RPC name service database. When this service is turned on, RPC clients can locate RPC servers. By default, this service is turned off.

System service name: RpcLocator

The RPC Locator service offers its services by using RPC over named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.

• Remote Storage Notification

The Remote Storage Notification system service notifies users when they read from or write to files that are available only from a secondary storage media. Stopping this service prevents this notification.

System service name: Remote_Storage_User_Link

• Remote Storage

The Remote Storage system service stores infrequently used files on a secondary storage medium. If you stop this service, users cannot move or retrieve files from the secondary storage media.

System service name: Remote_Storage_Server

• Routing and Remote Access

The Routing and Remote Access service provides multiprotocol LAN-to-LAN, LAN-to-WAN, VPN, and NAT routing services. The Routing and Remote Access service also provides dial-up and VPN remote access services. Although the Routing and Remote Access service can use all the following protocols, the service typically uses only a few of them. For example, if you configure a VPN gateway that is behind a filtering router, you will probably use only one protocol. If you use L2TP with IPsec, you must allow IPsec ESP (IP protocol 50), NAT-T (UDP on port 4500), and IPsec ISAKMP (UDP on port 500) through the router.

Although NAT-T and IPsec ISAKMP are required for L2TP, these ports are monitored by the Local Security Authority. For more information about this, see the References section.

System service name: RemoteAccess

The Server system service provides RPC support and file sharing, print sharing, and named pipe sharing over the network. The Server service lets users share local resources, such as disks and printers, so that other users on the network can access them. It also enables named pipe communication between programs that are running on the local computer and on other computers. Named pipe communication is memory that is reserved for the output of one process to be used as input for another process. The input-accepting process does not have to be local to the computer.

If a computer name resolves to multiple IP addresses by using WINS, or if WINS failed and the name is resolved by using DNS, NetBIOS over TCP/IP (NetBT) tries to ping the IP address or addresses of the file server. Port 139 communications depend on Internet Control Message Protocol (ICMP) echo messages. If IP version 6 (IPv6) is not installed, port 445 communications will also depend on ICMP for name resolution. Preloaded Lmhosts entries will bypass the DNS resolver. If IPv6 is installed on computers that are running Windows Server 2003 or Windows XP operating systems, port 445 communications do not trigger ICMP requests.

The NetBIOS ports that are listed here are optional. Windows 2000 and newer clients can work over port 445.

System service name: lanmanserver

SharePoint Portal Server

The SharePoint Portal Server system service lets you develop an intelligent portal that seamlessly connects users, teams, and knowledge. It helps people take advantage of relevant information across business processes. Microsoft SharePoint Portal Server 2003 provides an enterprise business solution that integrates information from various systems into one solution through single sign-on and enterprise application integration capabilities.

• Simple Mail Transfer Protocol (SMTP)

The Simple Mail Transfer Protocol (SMTP) system service is an email submission and relay agent. It accepts and queues email messages for remote destinations, and it retries at set intervals. Windows domain controllers use the SMTP service for intersite e-mail-based replication. The Collaboration Data Objects (CDO) for the Windows Server 2003 COM component can use the SMTP service to submit and to queue outgoing email messages.

System service name: SMTPSVC

Simple TCP/IP Services

Simple TCP/IP Services implements support for the following protocols:

• Echo, port 7, RFC 862
• Discard, port 9, RFC 863
• Character Generator, port 19, RFC 864
• Daytime, port 13, RFC 867
• Quote of the Day, port 17, RFC 865

System service name: SimpTcp

Simple Network Management Protocol (SNMP) Service

SNMP Service lets the local computer service incoming SNMP requests. SNMP Service includes agents that monitor activity in network devices and report to the network console workstation. SNMP Service provides a method of managing network hosts (such as workstation or server computers, routers, bridges, and hubs) from a centrally located computer that is running network management software. SNMP performs management services by using a distributed architecture of management systems and agents.

System service name: SNMP

SNMP Trap Service

SNMP Trap Service receives trap messages that are generated by local or by remote SNMP agents. Then the SNMP Trap Service forwards those messages to SNMP management programs that are running on your computer. When SNMP Trap Service is configured for an agent, the service generates trap messages if any specific events occur. These messages are sent to a trap destination. For example, an agent can be configured to start an authentication trap if an unrecognized management system sends a request for information. Trap destinations include the computer name, the IP address, or the Internetwork Packet Exchange (IPX) address of the management system. The trap destination must be a network-enabled host that is running SNMP management software.

System service name: SNMPTRAP

Simple Service Discovery Protocol (SSDP) Discovery Service

SSDP Discovery Service implements SSDP as a Windows service. SSDP Discovery Service manages receipt of device presence announcements, updates its cache, and sends these notifications to clients that have outstanding search requests. SSDP Discovery Service also accepts the registration of event callbacks from clients. The registered event callbacks are then turned into subscription requests. SSDP Discovery Service then monitors for event notifications and sends these requests to the registered callbacks. This system service also provides periodic announcements to hosted devices. Currently, the SSDP event notification service uses TCP port 5000.

Starting with Windows XP Service Pack 2 (SP2), the SSDP event notification service uses TCP port 2869.

System service name: SSDPRSR

TCP/IP Print Server

The TCP/IP Print Server system service enables TCP/IP-based printing by using the Line Printer Daemon (LPD) protocol. The LPD service on the server receives documents from Line Printer Remote (LPR) utilities that are running on UNIX computers.

System service name: LPDSVC

The Telnet system service for Windows provides ASCII terminal sessions to Telnet clients. A Telnet server supports two kinds of authentication and supports the following kinds of terminals:

• American National Standards Institute (ANSI)

System service name: TlntSvr

Remote Desktop Services (RDS)

RDS provides a multi-session environment that enables client devices to access a virtual Windows desktop session and Windows-based programs that are running on the server. RDS enables multiple users to be connected interactively to a computer.

System service name: TermService

RDS Licensing (RDSL)

The RDSL system service installs a license server and provides licenses to registered clients when the clients connect to a RDS server (a server that has RDS enabled). RDSL is a low-impact service that stores the client licenses that are issued for a RDS server and tracks the licenses that are issued to client computers or servers.

System service name: TermServLicensing

RDSL offers its services by using RPC over named pipes. This service has the same firewall requirements as the File and Printer Sharing feature.

• Remote Desktop Connection Broker

The Remote Desktop Connection Broker system service enables clusters of load-balanced RDS servers to correctly route a user's connection request to the server where the user already has a session running. Users are routed to the first-available RDS server regardless of whether they are running another session in the server cluster. The load-balancing functionality pools the processing resources of several servers by using the TCP/IP networking protocol. You can use this service together with a cluster of RDS servers to increase the performance of a single RDS server by distributing sessions across multiple servers. Remote Desktop Connection Broker keeps track of disconnected sessions on the cluster and makes sure that users are reconnected to those sessions.

System service name: Tssdis

Trivial FTP Daemon

The Trivial FTP Daemon system service does not require a user name or a password and is an important part of the Remote Installation Services (RIS). The Trivial FTP Daemon service implements support for the Trivial FTP Protocol (TFTP) that is defined by the following RFCs:

• RFC 1350 - TFTP
• RFC 2347 - Option extension
• RFC 2348 - Block size option
• RFC 2349 - Time-out interval, and transfer size options

Trivial File Transfer Protocol (TFTP) is an FTP that supports diskless startup environments. The TFTP service listens on UDP port 69, but it responds from a randomly allocated high port. Therefore, when you enable this port, the TFTP service receives incoming TFTP requests, but it does not let the selected server respond to those requests. The service is free to respond to any such request from any source port, and the remote client then uses that port during the transfer. Communication is bidirectional. If you have to enable this protocol through a firewall, you may want to open UDP port 69 incoming. You can then rely on other firewall features that dynamically let the service respond through temporary holes on any other port.

System service name: tftpd

UPnP Device Host

The UPnP Device Host discovery system service implements all the components that are required for device registration, control, and the response to events for hosted devices. The information that is registered that relates to a device, such as the description, the lifetimes, and the containers, are optionally stored to disk and are announced on the network after registration or when the operating system restarts. The service also includes the web server that serves the device in addition to service descriptions and a presentation page.

System service name: UPNPHost

Windows Internet Name Service (WINS)

Windows Internet Name Service (WINS) enables NetBIOS name resolution. This service helps you locate network resources by using NetBIOS names. WINS servers are required unless all domains have been upgraded to the Active Directory directory service and unless all computers on the network are running Windows 2000 or later versions. WINS servers communicate with network clients by using NetBIOS name resolution. WINS replication is only required between WINS servers.

System service name: WINS

Windows Media Services

Windows Media Services in Windows Server 2003 and later versions replaces the following services that are included in Windows Media Services versions 4.0 and 4.1:

• Windows Media Monitor Service
• Windows Media Program Service
• Windows Media Station Service
• Windows Media Unicast Service

Windows Media Services is now a single service that runs on Windows Server. Its core components were developed by using COM, and it has a flexible architecture that you can customize for specific programs. Windows Media Services supports a larger variety of control protocols. These include Real Time Streaming Protocol (RTSP), Microsoft Media Server (MMS) protocol, and HTTP.

System service name: WMServer

Windows Remote Management (WinRM)

System service name: WinRM

For more information, see Installation and Configuration for Windows Remote Management .

• Windows Time

The Windows Time system service maintains date and time synchronization on all the computers on a network that are running Windows XP or later versions and Windows Server 2003 or later versions. This service uses Network Time Protocol (NTP) to synchronize computer clocks so that an accurate clock value, or time stamp, is assigned for network validation and for resource access requests. The implementation of NTP and the integration of time providers help make Windows Time a reliable and scalable time service for your business. For computers that are not joined to a domain, you can configure Windows Time to synchronize time with an external time source. If this service is turned off, the time setting for local computers is not synchronized with a time service in the Windows domain or with an externally configured time service. Windows Server 2003 uses NTP. NTP runs on UDP port 123. The Windows 2000 version of this service uses Simple Network Time Protocol (SNTP). SNTP also runs on UDP port 123.

When the Windows Time service uses a Windows domain configuration, the service requires domain controller location and authentication services. Therefore, the ports for Kerberos and DNS are required.

System service name: W32Time

• World Wide Web Publishing Service

World Wide Web Publishing Service provides the infrastructure that you must have to register, manage, monitor, and serve websites and programs that are registered with IIS. This system service contains a process manager and a configuration manager. The process manager controls the processes where custom applications and websites reside. The configuration manager reads the stored system configuration for World Wide Web Publishing Service and makes sure that Http.sys is configured to route HTTP requests to the appropriate application pools or operating system processes. You can use the Internet Information Services (IIS) Manager snap-in to configure the ports that are used by this service. If the administrative website is enabled, a virtual website is created that uses HTTP traffic on TCP port 8098.

System service name: W3SVC

Ports and protocols

The following table summarizes the information from the System services ports section. This table is sorted by port number instead of by service name.

Port 5722 is only used on a Windows Server 2008 domain controller or a Windows Server 2008 R2 domain controller; it is not used on a Windows Server 2012 domain controller. Port 445 is used by DFSR only when creating a new empty replicated folder.

Microsoft provides part of the information that is in this table in a Microsoft Excel worksheet. This worksheet is available for download from the Microsoft Download Center.

Active Directory port and protocol requirements

Application servers, client computers, and domain controllers that are located in common or external forests have service dependencies so that user-initiated and computer-initiated operations such as domain join, logon authentication, remote administration, and Active Directory replication work correctly. Such services and operations require network connectivity over specific port and networking protocols.

A summarized list of services, ports, and protocols required for member computers and domain controllers to inter-operate with one another or for application servers to access Active Directory include but are not limited to the following.

The list of services on which Active Directory depends:

• Active Directory / LSA
• Distributed File System Replication (if not using FRS for SYSVOL replication)
• File Replication Service (if not using DFSR for SYSVOL replication)
• WINS (in Windows Server 2003 SP1 and later versions for backup Active Directory replication operations, if DNS is not working)

The list of services that require Active Directory services:

• Certificate Services (required for specific configurations)
• DHCP Server
• Distributed File System Namespaces (if using domain-based namespaces)
• File Replication Service

The Help files for each Microsoft product that is described in this article contain more information that you may find useful to help configure your programs.

For information about Active Directory Domain Services firewalls and ports, see How to configure a firewall for Active Directory domains and trusts .

General information

For more information about how to help secure Windows Server and for sample IPsec filters for specific server roles, see Microsoft Security Compliance Manager . This tool aggregates all previous security recommendations and security documentation into a single utility for all support Microsoft operating systems:

• Windows security baselines
• Windows Server 2008 R2 Security Baseline
• Windows Server 2008 Security Baseline
• Windows Server 2003 Security Baseline
• Windows 7 Security Baseline
• Windows Vista Security Baseline
• Windows XP Security Baseline

For more information about operating system services, security settings, and IPsec filtering, see one of the following Threats and Countermeasures Guides:

• Threats and Countermeasures Guide: Security Settings in Windows Server 2008 R2 and Windows 7
• Threats and Countermeasures Guide: Security Settings in Windows Server 2008 and Windows Vista
• Threats and Countermeasures: Security Settings in Windows Server 2003 and Windows XP

For more information, see:

• Network Ports Used by Key Microsoft Server Products
• Active Directory and Active Directory Domain Services Port Requirements .

The Internet Assigned Numbers Authority coordinates the use of well-known ports. To view this organization's list of TCP/IP port assignments, see Service Name and Transport Protocol Port Number Registry .

Remote Procedure Calls and DCOM

For a detailed description of RPC, see Remote Procedure Call (RPC) .

For more information about how to configure RPC to work with a firewall, see How to configure RPC dynamic port allocation to work with firewalls .

For more information about the RPC protocol and about how computers that are running Windows 2000 initialize, see Windows 2000 Startup and Logon Traffic Analysis .

Domain controllers and Active Directory

For more information about how to restrict Active Directory replication and client logon traffic, see Restricting Active Directory replication traffic and client RPC traffic to a specific port .

For an explanation of how the Directory System Agent, LDAP, and the local system authority are related, see Directory System Agent .

For more information about how LDAP and the global catalog work, see How the Global Catalog works .

Exchange Server

For information about ports, authentication, and encryption for all data paths that are used by Microsoft Exchange Server, see Network ports for clients and mail flow in Exchange .

There may be additional things to consider for your particular environment. You can receive more information and help planning an Exchange implementation from the following Microsoft websites:

• Exchange Server 2013
• Exchange Server 2007
• Exchange Server 2003

For more information, see Configure Outlook Anywhere in Outlook 2013 .

Distributed File Replication Service

The Distributed File Replication Service includes the Dfsrdiag.exe command-line tool. Dfsrdiag.exe can set the server RPC port that is used for administration and replication. To use Dfsrdiag.exe to set the server RPC port, follow this example:

dfsrdiag StaticRPC/port: nnnnn /Member: Branch01.sales.contoso.com

In this example, nnnnn represents a single, static RPC port that DFSR will use for replication. Branch01.sales.contoso.com represents the DNS or NetBIOS name of the target member computer. If no member is specified, Dfsrdiag.exe uses the local computer.

Internet Information Services

For information about ports in IIS 6.0, see TCP/IP Port Filtering .

For information about FTP, see the following resources:

• FTP Publishing Service webpage
• Configuring FTP Firewall Support

Multicast Address Dynamic Client Allocation Protocol (MADCAP)

For more information about how to plan MADCAP servers, see Checklist: Installing a MADCAP server .

For more information about the ports that are used by Microsoft Message Queuing, see TCP ports, UDP ports, and RPC ports that are used by Message Queuing .

Microsoft Operations Manager

For information about how to plan for and to deploy MOM, see System Center Developer Documentation Library .

For more information about how to configure the port that is used by RDS, see Change the listening port for Remote Desktop on your computer .

Controlling communications over the Internet in Windows

For more information, see the Using Windows Server 2003 with Service Pack 1 in a Managed Environment: Controlling Communication with the Internet .

For information about the ports that are used by Windows Media Services, see Allocating Ports for Windows Media Services .

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Additional resources

Port Types & Classification

A port is a communication point where one or more computers in a network talk with each other through a program or software. There are about 0-65535 ports assigned to do specific tasks in a PC. Most ports operate with TCP or UDP protocol.

Port numbers are officialy assigned by an organisation called IANA and ports are allocated to various needs to avoid confusion.

Ports are classified into 3 main categories..

• Well Known Ports (Port numbers 0 – 1023)
• Registered Ports (Port numbers1024 – 49151)
• Private or Dynamic Ports (Port numbers 49152 – 65535)

Well Known Ports Well known ports are used by system or processes run by root or with specific previleges. The port numbers range from 0 to 1023 .

Registered Ports The registered port numbers range from 1024-49151. Such ports are used by programs run by users in the system.

Private/Dynamic Ports Private ports are not assigned for any specific purpose. its range are from range 49152?65535

Difference TCP vs UDP Protocol

Commonly Used Port Numbers

The following port numbers are unofficial list of commonly used for linux/unix based servers.

More unofficial list of ports and assignments s available  here Official ports and its assignments are published at the  IANA website .

Note : The above published ones are unofficial list compiled from various sources.

• Privacy Policy
• Terms & Conditions

Port Number Lookup

If you are not sure that Port Numbers you are going to use has been assignned for what purpose. You can lookup our TCP ports database and find details related to assignment Port or Protocol assigned by IANA (Internet Assigned Numbers Authority).

Port Numbers and Protocols

TCP and UDP are two different protocols that are used for transmitting data over a network. TCP (Transmission Control Protocol) is a connection-oriented protocol that ensures that data is delivered reliably and in the correct order. UDP (User Datagram Protocol) is a connectionless protocol that does not guarantee the delivery of data or the order in which it is delivered.

Here are some common port numbers that are used by TCP and UDP:

TCP port numbers:

• Port 80: HTTP (Hypertext Transfer Protocol)
• Port 443: HTTPS (HTTP Secure)
• Port 21: FTP (File Transfer Protocol)
• Port 22: SSH (Secure Shell)
• Port 25: SMTP (Simple Mail Transfer Protocol)
• Port 155: NETSC

UDP port numbers:

• Port : DNS (Domain Name System)
• Port 67: DHCP (Dynamic Host Configuration Protocol)
• Port 69: TFTP (Trivial File Transfer Protocol)
• Port 123: NTP (Network Time Protocol)

Note that these are just a few examples, and there are many other port numbers that are used for various purposes.

For port numbers lookup, the official database of ports and protocols from IANA (Internet Assigned Numbers Authority) is used. IANA is an organization that manages Internet protocol parameters, as well as IP address spaces and top-level domains.

Diffrent Port Number Ranges?

The entire range of port numbers (from 0 to 65535) is divided into three categories.

0 - 1023  Well-Known Ports The  numbers are reserved by IANA for system processes or network programs with administrative rights. Ports from this category should not be used without registering with IANA.

1024 - 49151  Registered Ports  Ports registered for use by conventional programs and application layer protocols. This category of ports is most popular for commercial software. Registration is also required to use any port.

49152 - 65535  Dynamic ports  Designed for free but temporary use. Registration of ports in this category is not possible.

Our Port checker tool allows you to test open ports in your system. You can easily verify if any port is opened or not not by typing your IP address or domain name and desired port number.

Transport Area Working Group M. Cotton Internet-Draft ICANN Updates: (if approved) L. Eggert Intended status: BCP Nokia Expires: August 21, 2008 A. Mankin   NSF   M. Westerlund   Ericsson   February 18, 2008 IANA Allocation Guidelines for TCP and UDP Port Numbers draft-cotton-tsvwg-iana-ports-00 Status of this memo. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as “work in progress.” The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt . The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html . This Internet-Draft will expire on August 21, 2008. This document defines the IANA guidelines for registering new port number values for use with the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). It provides clear processes for the TCP and UDP port number registries, important for their long-term management. It updates RFC2780 by replacing Sections 8 and 9.1 of that RFC. Table of Contents 1.   Introduction 2.   Terminology 3.   Stewardship Principles for the Port Number Space 4.   Allocation Procedures for the Port Number Space      4.1.   Common Procedures      4.2.   Well Known (System) Ports      4.3.   Registered (User) Ports      4.4.   Dynamic (Private) Ports 5.   Supplemental Procedures for the Port Number Space      5.1.   Port Number De-Registration      5.2.   Port Number Re-Use      5.3.   Port Number Revocation 6.   Security Considerations 7.   IANA Considerations 8.   Acknowledgments 9.   References      9.1.   Normative References      9.2.   Informative References Appendix A.   Open Issues §   Authors' Addresses §   Intellectual Property and Copyright Statements 1.  Introduction The Transmission Control Protocol (TCP) [RFC0793] ( Postel, J., “Transmission Control Protocol,” September 1981. ) and the User Datagram Protocol (UDP) [RFC0768] ( Postel, J., “User Datagram Protocol,” August 1980. ) have enjoyed a remarkable success over the decades as the two most widely used transport protocols on the Internet. They have introduced the concept of ports as logical entities that end system applications bind their transport sessions to. Ports are identified by 16-bit numbers, and the combination of source and destination port numbers together with the IP addresses communicating end systems uniquely identifies a session of a given transport protocol. Newer transport protocols, such as the Stream Control Transmission Protocol (SCTP) [RFC4960] ( Stewart, R., “Stream Control Transmission Protocol,” September 2007. ) and the Datagram Congestion Control Protocol (DCCP) [RFC4342] ( Floyd, S., Kohler, E., and J. Padhye, “Profile for Datagram Congestion Control Protocol (DCCP) Congestion Control ID 3: TCP-Friendly Rate Control (TFRC),” March 2006. ) have adopted the concept of ports for their communication sessions and use port numbers in the same way as TCP and UDP. Port numbers are the original and most widely used means for application and service identification on the Internet. Designers of applications and application-level protocols may apply to the Internet Assigned Numbers Authority (IANA) for a registered port number for a specific application, and may after successful registration assume that no other application will use that port number for its communication sessions. It is important to note that ownership of registered port numbers remains with IANA. For many years, the allocation and registration of new port number values for use with TCP and UDP have had less than clear guidelines. Information about the registration procedures for the port namespace existed in three locations: the forms for requesting port number registrations on the IANA web site [SYSFORM] ( Internet Assigned Numbers Authority (IANA), “Application for System (Well Known) Port Number,” . ) [USRFORM] ( Internet Assigned Numbers Authority (IANA), “Application for User (Registered) Port Number,” . ) , an introductory text section in the file listing the port number registrations themselves [REGISTRY] ( Internet Assigned Numbers Authority (IANA), “Port Numbers,” . ) , and two brief sections of [RFC2780] ( Bradner, S. and V. Paxson, “IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers,” March 2000. ) . This document aggregates this scattered information into a single reference and at the same time clarifies the guidelines for the management of the TCP and UDP port number space. It gives more detailed guidance to prospective requesters of TCP and UDP ports than the existing documentation, and it streamlines the IANA procedures for the management of the port number space, so that management requests can complete in a timely manner. A key factor of this streamlining is to establish identical registration procedures for transport protocol ports, independent of a specific transport protocol. This document brings the IANA procedures for TCP and UDP in line with those already in effect for SCTP and DCCP, resulting in a single process that requesters and IANA follow for all port number requests for all transport protocols. A second purpose of this document is to describe the principles that guide the IETF and IANA in their role as the long-term joint stewards of the port number space. TCP and UDP have been a remarkable success over the last decades. Thousands of applications and application-level protocols have registered ports for their use, and there is every reason to believe that this trend will continue into the future. It is hence extremely important that management of the port number space follow principles that ensure its long-term usefulness as a shared resource. Section 3 ( Stewardship Principles for the Port Number Space ) discusses these principles in detail. TCP and UDP use 16-bit namespaces for their port number registries, as do SCTP and DCCP. These ports registries are subdivided into three port number ranges, and Section 4 ( Allocation Procedures for the Port Number Space ) describes the IANA procedures for each range in detail: the Well Known Ports, aka the System Ports, from 0-1023 the Registered Ports, aka the User Ports, from 1024-49151 the Dynamic Ports, aka the Private Ports, from 49152-65535 When this document was being written, approximately 76% of the Well Known Ports for TCP and UDP were assigned, as was a significant fraction of the Registered Ports. (Dynamic Ports are not available for assignment through IANA.) In addition to detailing the IANA procedures for the initial assignment of port numbers, this document also specifies supplemental procedures that until now have been handled in an ad hoc manner. These include procedures to de-register a port number that is no longer in use, to re-use a port number allocated for one application that is no longer in use for another application, and procedure by which IANA can unilaterally revoke a prior port number registration. Section 5 ( Supplemental Procedures for the Port Number Space ) discusses the specifics of these procedures. Finally, this document also addresses two technical issues with ports registry that are tangential to long-term stewardship. First, it clarifies that a method for the early allocation of TCP and UDP ports for IETF working group documents is available, in line with [RFC4020] ( Kompella, K. and A. Zinin, “Early IANA Allocation of Standards Track Code Points,” February 2005. ) . Second, it discusses how the use of the symbolic names for assigned ports (the "keyword" field in [REGISTRY] ( Internet Assigned Numbers Authority (IANA), “Port Numbers,” . ) ) for Service Resource Records (SRV RRs) in the Domain Name System (DNS) [RFC2782] ( Gulbrandsen, A., Vixie, P., and L. Esibov, “A DNS RR for specifying the location of services (DNS SRV),” February 2000. ) relates to the use of SRV RRs for applications without an assigned port. This document updates [RFC2780] ( Bradner, S. and V. Paxson, “IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers,” March 2000. ) by replacing Sections 8 and 9.1 of that RFC. Note that [I‑D.arkko‑rfc2780‑proto‑update] ( Arkko, J. and S. Bradner, “IANA Allocation Guidelines for the Protocol Field,” January 2008. ) updates a different subset of the IANA allocation guidelines originally given in [RFC2780] ( Bradner, S. and V. Paxson, “IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers,” March 2000. ) (specifically, the policies on the namespace of the IP protocol number and IPv6 next header). 2.  Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, RFC 2119 [RFC2119] ( Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997. ) . 3.  Stewardship Principles for the Port Number Space The overriding principle that governs the IANA and IETF procedures governing the management of the port number registry for the different transport protocols is conservation. The port number registry is one of the basic resources of the Internet and requires careful management. Exhaustion is likely to require fundamental changes to Internet communication, which is undesirable. At the same time, it is of great benefit to all Internet applications to request and receive port number allocations from IANA for their communication needs. This means that although IANA should require and verify that applicants for port numbers document their intended use to a degree that lets a technical expert review the desired allocation, this process must not appear to be an insurmountable burden. Otherwise, there is the danger that application designers turn to using ports in an undocumented fashion, which is harmful to Internet communications as a whole. Clearly stated and motivated procedures support this goal. It is important to note that different IANA procedures apply to different ranges of the port number registry. Section 4 ( Allocation Procedures for the Port Number Space ) discusses the details of these procedures; this section outlines the rationale for these differences: Ports in the Dynamic Ports range (49152-65535) have been specifically set aside for local and dynamic use and cannot be registered through IANA. Applications may simply use them for communication without any sort of registration. On the other hand, applications must not assume that a specific port number in the Dynamic Ports range will always be available for communication at all times, and a port number in that range hence cannot be used as a service identifier. Ports in the Registered Ports range (1024-49151) are available for registration through IANA, and can be used as service identifiers upon successful registration. Because registering a port number for a specific application consumes a fraction of the shared resource that is the port number registry, IANA will require the requester to document the intended use of the port number, and have a technical expert review this documentation to determine whether to grant the registration request. This documentation must explain why a port number in the Dynamic Ports range is unsuitable for the given application. Ports in the Well Known Ports range (0-1023) are also available for registration through IANA. Because the Well Known Ports range is both the smallest and the most densely allocated one, the bar for new allocations is higher than that for the Registered Ports range (1024-49551). A request for a Well Known port number must document why a port number in the Registered Ports of Dynamic Ports ranges are unsuitable. Several other practices stem from the conservation principle that guides management of the port numbers registry. First, with the approval of this document, IANA will begin assigning protocol numbers only for those transport protocols explicitly included in the registration request. This ends the long-standing practice of automatically assigning a port number to an application for both TCP and a UDP, even if the request is only for one of these transport protocols. The new allocation procedure conserves resources by only allocating a port number to an application for those transport protocols (TCP, UDP, SCTP and/or DCCP) it actually uses. The port number will be marked as reserved - instead of assigned - in the port number registries of the other transport protocols. When applications start supporting the use of some of those additional transport protocols, they must request IANA to convert the reservation to an assignment. An application must not assume that it can use a port number assigned to it for use with one transport protocol with another transport protocol without a registration with IANA. Second, IANA will continue its long-standing practice of refusing allocations for applications that request the assignments of multiple port numbers. Registered port numbers are application identifiers, and extremely few applications require multiple identifiers. For applications that do require a registered port number in the first place, the vast majority of them can operate without restrictions using a single registered port number. Such applications can often simply use several ports taken on-demand from the Dynamic Ports range, or they can use a demultiplexing field that is part of their packet payload. Third, conservation for the port numbers registry is improved by procedures that allow previously allocated port numbers to become unassigned, either through de-registration or revocation, and by a procedure that lets application designers transfer an unused port number to a new application. Section 5 ( Supplemental Procedures for the Port Number Space ) describes these procedures, which so far were undocumented. 4.  Allocation Procedures for the Port Number Space 4.1.  common procedures. All registration requests for a TCP and/or UDP ports must contain the following pieces of information: Registration Contact: Name and email address of the contact for the registration. This is mandatory. Additional address information may be provided. For registrations done through IETF-published RFCs, one or more technical contact persons shall be provided. In addition, in this case the registration ownership will belong to the IETF and not the technical contact persons. Transport Protocol: Which transport protocol(s) is the registration request for, TCP, UDP or both? Broadcast or Multicast: If multicast or broadcast is used with the registered port, a description of this usage is required. Port Name: The long name (description) of the port. It should avoid all but the most well known acronyms. Service Name: This short name for the port number is used in the service name registry for DNS SRV RRs and has a 14-character maximum length. It must not conflict with already-allocated names in the service name registry [TBD]. Note that a particular application or service should be able to operate using only one well known or registered port. For applications or services that offer multiple functions, it is usually possible to use one port number for a multiplexing or rendezvous service. That is, the client always initiates the use of a service by contacting the rendezvous port number with a message that indicates which function is needed. The rendezvous service then either (A) creates (forks, spawns) a process to perform that function and passes the connection to it; or (B) dynamically selects a (high-numbered) port and starts a process to listen on that port number and then sends a message back to the client telling it to contact the new process on that port number. When a registration for only TCP or UDP is approved, the port number for the other transport protocol will remain unassigned but is marked as reserved. However, IANA SHOULD NOT assign that port number to any other application or service until no port numbers exist in the request range that are u for both protocols. The current registration owner of a port number MAY register the same port number for other transport protocols when needed. 4.2.  Well Known (System) Ports The Well Known Ports are assigned by IANA and cover the range 0-1023. On many systems, they can only be used by system (or root) processes or by programs executed by privileged users. Registration requests for a Well Known port number MUST follow the "IETF Review" policy of [I‑D.narten‑iana‑considerations‑rfc2434bis] ( Narten, T. and H. Alvestrand, “Guidelines for Writing an IANA Considerations Section in RFCs,” March 2008. ) . Registrations for a port number in this range MUST document why a port number in the Registered Ports range will not fulfill the application needs. Registrations requesting more than a single port number for a single application in this space SHOULD be denied. Because of the special nature of port numbers in the Well Known range on several platforms, [RFC4727] ( Fenner, B., “Experimental Values In IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers,” November 2006. ) has registered two port numbers in this range (1021 and 1022) for temporary, experimental use. Use of these two port numbers must comply to the guidelines set out in [RFC3692] ( Narten, T., “Assigning Experimental and Testing Numbers Considered Useful,” January 2004. ) , most importantly, they are not intended to be used in general deployments or be enabled by default in products or other general releases. The other restrictions as defined in [RFC3692] ( Narten, T., “Assigning Experimental and Testing Numbers Considered Useful,” January 2004. ) apply as well. 4.3.  Registered (User) Ports The Registered Ports are assigned by IANA and on most systems can be used by ordinary user processes or programs executed by ordinary users. The Registered Ports are in the range 1024-49151. This port number range is the main range for any application or service requiring a known and stable port number across all hosts. Before requesting a registration, requesters should carefully consider if a rendezvous mechanism, such as DNS SRV RRs, together with the use of port numbers in the Dynamic Ports range can satisfy the application requirements. It is expected that primarily rendezvous or look-up services or applications and services that must operate in environments where such services are unavailable will need to use registered ports. Registration requests for a Registered Port number MUST follow the "Expert Review" policy of [I‑D.narten‑iana‑considerations‑rfc2434bis] ( Narten, T. and H. Alvestrand, “Guidelines for Writing an IANA Considerations Section in RFCs,” March 2008. ) . Registration requests for more than a single port number for a single application are NOT RECOMMENDED and MUST come with an extremely strong justification when brought forward. 4.4.  Dynamic (Private) Ports The Dynamic Ports range from 49152-65535. These ports cannot be registered through IANA or by any other means. IANA SHALL refuse all such registration requests. Private ports are usable by any application in a dynamic fashion. Usage of private ports for server type applications or services are possible through the use of rendezvous or location look-up mechanisms, e.g., the DNS. Applications acquire a particular dynamic port number on an end system and register the port number of the contact port for that service with a rendezvous or look-up service. It is RECOMMENDED that application that are capable of using such mechanisms utilize them, in order to minimize consumption of the finite port number space. 5.  Supplemental Procedures for the Port Number Space 5.1.  port number de-registration. The original requesters of a granted port number assignment can return the port number to IANA at any time if there no longer is a need for it. The port number will be de-registered and will be marked as unassigned. IANA will not assign port numbers that have been de-registered until all other available port numbers in the specific range have been assigned. Before proceeding with a de-registration, IANA needs to confirm that the port number is actually no longer in use. 5.2.  Port Number Re-Use If the original requesters of a granted port number assignment no longer have a need for the registered number, but would like to re-use it for a different application, they can submit a request to IANA to do so. Logically, port number re-use is to be thought of as a de-registration followed by an immediate re-registration of the same port number for a new application. Consequently, the information that needs to be provided about the proposed new use of the port number is identical to what would need to be provided for a new port number allocation for the specific ports range. IANA needs to carefully review such requests before approving them. In some instances, the Expert Reviewer will determine that the application that the port number was assigned to has found usage beyond the original requester, or that there is a concern that it may have such users. This determination MUST be made quickly. A community call concerning revocation of a port number (see below) MAY be considered, if a broader use of the port number is suspected. 5.3.  Port Number Revocation Often, it will be clear that a specific port number is no longer in use and that IANA can de-register it and mark it as unassigned. But at other times, it may be unclear whether a given assigned port number is still in use somewhere in the Internet. In those cases, despite the requester's wish to de-register, IANA must consider the consequences that de-registering the port number. With the help of their IESG-appointed Expert Reviewer, IANA SHALL formulate a request to the IESG to issue a four-week community call concerning the pending port number revocation. The IESG and IANA, with the Expert Reviewer's support, SHALL determine promptly after the end of the community call whether de-registration should proceed and then communicate their decision to the community 6.  Security Considerations The IANA guidelines described in this document do not change the security properties of either TCP or UDP. Assignment of a port number does not in any way imply an endorsement of an application or product, and the fact that network traffic is flowing to or from a registered port number does not mean that it is "good" traffic. Firewall and system administrators should choose how to configure their systems based on their knowledge of the traffic in question, not whether there is a port number registered or not. 7.  IANA Considerations This document obsoletes Sections 8 and 9.1 of [RFC2780] ( Bradner, S. and V. Paxson, “IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers,” March 2000. ) . Upon approval of this document, IANA is requested to adopt the procedures described herein. Values in the UDP Source and Destination Field may be assigned Values in the TCP Source and Destination Field may be assigned Upon approval of this document or sooner, the IESG SHALL appoint a TCP/UDP Ports Expert Reviewer to work with IANA in support of the port registry and to uphold the principles described in this document. The Expert Reviewer will provide rapid advice to IANA as to whether to grant a port number assignment, including whether requests for more than one transport are merited. IANA MAY ask the TCP/UDP Expert Reviewer to co-review an SCTP or DCCP request if it also asks for a TCP or UDP port. The Expert Reviewer SHALL support IANA in the analysis for determining when a request to re-purpose a port number or de-assign it requires a community call on port number revocation. 8.  Acknowledgments Lars Eggert is partly funded by [TRILOGY] ( , “Trilogy Project,” . ) , a research project supported by the European Commission under its Seventh Framework Program. 9.  References 9.1. normative references. Narten, T. and H. Alvestrand, “ ,” draft-narten-iana-considerations-rfc2434bis-09 (work in progress), March 2008 ( ). Postel, J., “ ,” STD 6, RFC 768, August 1980 ( ). Postel, J., “ ,” STD 7, RFC 793, September 1981 ( ). , “ ,” BCP 14, RFC 2119, March 1997 ( , , ). and , “ ,” BCP 37, RFC 2780, March 2000 ( ). Kompella, K. and A. Zinin, “ ,” BCP 100, RFC 4020, February 2005 ( ). Fenner, B., “ ,” RFC 4727, November 2006 ( ). 9.2. Informative References Arkko, J. and S. Bradner, “ ,” draft-arkko-rfc2780-proto-update-02 (work in progress), January 2008 ( ). Internet Assigned Numbers Authority (IANA), “Port Numbers,”  http://www.iana.org/assignments/port-numbers. , Vixie, P., and , “ ,” RFC 2782, February 2000 ( ). Narten, T., “ ,” BCP 82, RFC 3692, January 2004 ( ). Floyd, S., Kohler, E., and J. Padhye, “ ,” RFC 4342, March 2006 ( ). Stewart, R., “ ,” RFC 4960, September 2007 ( ). Internet Assigned Numbers Authority (IANA), “Application for System (Well Known) Port Number,”  http://www.iana.org/cgi-bin/sys-port-number.pl. “Trilogy Project,”  http://www.trilogy-project.org/. Internet Assigned Numbers Authority (IANA), “Application for User (Registered) Port Number,”  http://www.iana.org/cgi-bin/usr-port-number.pl. Appendix A.  Open Issues This document is an initial version submitted for discussion at IETF-71 in Philadelphia, PA, USA. Expect nearly all sections of this document to see significant revisions in the near future. Nothing in here is final. Authors' Addresses   Michelle Cotton   Internet Corporation for Assigned Names and Numbers   4676 Admiralty Way, Suite 330   Marina del Rey, CA 90292   USA Phone:  +1 310 823 9358 Email:  URI:        Lars Eggert   Nokia Research Center   P.O. Box 407   Nokia Group 00045   Finland Phone:  +358 50 48 24461 Email:  URI:        Allison Mankin   National Science Foundation   4102 Wilson Boulevard   Arlington, VA 22230   USA Phone:  +1 301 728 7199 Email:  URI:        Magnus Westerlund   Ericsson   Torshamsgatan 23   Stockholm 164 80   Sweden Phone:  +46 8 719 0000 Email:  Full Copyright Statement Copyright © The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an “AS IS” basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr . The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at [email protected] . Networking Bible by Barrie Sosinsky Get full access to Networking Bible and 60K+ other titles, with a free 10-day trial of O'Reilly. There are also live events, courses curated by job role, and more. Appendix A. TCP - UDP Port Assignments IN THIS APPENDIX Different port assignments are listed Table A.1 lists many common ports in use for both the TCP and UDP protocols, under the Port column as T and U, respectively. The most widely used ports are typically found in the range 1 to 1023 and are referred to as the "well-known ports." A large range of port assignments are registered by vendors for specific applications. Over time, many of these port assignments become just as popular as well-known ports. Registered ports are found in the range 1024 to 49191. Finally, ICANN allows the remaining ports from 49152 to 65535 to be used either dynamically or for private assignments. Ports in the high range are not registered or assigned; they are for use by anyone at any time. In many instances, TCP and UDP use the same numbers for the same protocol, but not always. Nor is a single protocol such as HTTP necessarily found on only one port assignment. There can be multiple ports assigned, and in the case of HTTP, the two common port assignments are not a contiguous range: both 80 and 8080 (for firewalls) are commonly used. Table A.1. Well-Known Ports: 1 to 1023 Registered Ports: 1024 to 49191 Dynamic and Private Ports: 49152 to 65535 (unassigned) Port Assignment Notes Reference: . The list above is edited and is not as complete as the list of ports on this official site. Also, their list is updated on a regular basis. 0 - T, U Reserved   0 - T, U Shirt Pocket netTunes; ... Get Networking Bible now with the O’Reilly learning platform. O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers. Don’t leave empty-handed Get Mark Richards’s Software Architecture Patterns ebook to better understand how to design components—and how they should interact. It’s yours, free. Check it out now on O’Reilly Dive in for free with a 10-day trial of the O’Reilly learning platform—then explore all the other resources our members count on to build skills and solve problems every day. Internet Assigned Numbers Authority (IANA) The IANA assigns a lot of different numbers (and the like) related to network protocols. Widely known are the well known TCP / UDP port assignments (see PortReference ), such as the assignment of TCP port 80 as the standard port for HTTP traffic. In addition to this, the IANA has made a number of other assignments: Protocol numbers for protocols running on top of IP Media types used in HTTP , SIP , e-mail, WSP , MMSE and many other protocols The assigned numbers (including the port numbers) were once reported using RFC documents. Several of such obsoleted RFCs exists (1700, 1340, 1060, 1010, 990, 960, 943, 923, 900, 870, 820, 790, 776, 770, 762, 758,755, 750, 739, 604, 503, 433, 349). Today, the IANA keeps "living documents" of assigned numbers on their webpage. External Links RFC1700 : Last RFC containing assigned numbers (obsoleted by IANA list). RFC3232 : States that RFC1700 is obsoleted by the IANA list. IANA list of assigned numbers : Official lists of assigned numbers and the like. Imported from https://wiki.wireshark.org/IANA on 2020-08-11 23:14:55 UTC Service Name and Transport Protocol Port Number Registry 108 IMAGES Common & Popular Ports Number used in OS List of TCP Ports and UDP Ports (Well-Known) What is UDP Scanning? Computer Science and Engineering: TCP UDP port Cos’è l’attacco UDP flood: funzionamento e protezione UDP traffic with source and destination ports of 54915 VIDEO Augmented Reality Mobile Application Tutorial Assignment 1 Part2: Port Forwarding Configuration How to remove VLAN assignment CCNA(SRWE)_VALN Part 2 Visit Ellesmere Port (Visit California Spoof) COMMENTS Service Name and Transport Protocol Port Number Registry services that run over transport protocols such as TCP, UDP, DCCP, and. SCTP. Service names are assigned on a first-come, first-served process, as. documented in [RFC6335]. Port numbers are assigned in various ways, based on three ranges: System. Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private. List of TCP and UDP port numbers They usually use port numbers that match the services of the corresponding TCP or UDP implementation, if they exist. The Internet Assigned Numbers Authority (IANA) is responsible for maintaining the official assignments of port numbers for specific uses. [1] However, many unofficial uses of both well-known and registered port numbers occur in ... Understanding TCP/UDP Client Port Assignment Client/server is an application concept. Next, port numbers for TCP and UDP are really addresses for the process attached to the transport protocol. The port numbers are per protocol, so TCP 12345 is not TCP 12345. A process attached to a port number of either protocol exclusively uses that port number for that protocol. - Ron Maupin. Well-known port assignments This topic lists the well-known port assignments for transport protocols TCP and UDP, and includes port number, keyword, and a description of the reserved port assignment. You can also find a list of these well-known port numbers in the hlq.ETC.SERVICES data set. The official assignment of port numbers is managed by the Internet Assigned ... RFC 6335: Internet Assigned Numbers Authority (IANA ... RFC 6335 Service Name and Port Number Procedures August 2011 1.Introduction For many years, the assignment of new service names and port number values for use with the Transmission Control Protocol (TCP) [] and the User Datagram Protocol (UDP) [] has had less than clear guidelines.New transport protocols have been added -- the Stream Control Transmission Protocol (SCTP) [] and the Datagram ... Well-known UDP port assignments Well-known UDP port assignments z/OS Communications Server: IP Programmer's Guide and Reference SC27-3659-02 Table 1 lists the well-known port assignments for UDP. Table 1. Well-known UDP port assignments; Port number Keyword Assigned to Services description; 0 : reserved : 5: rje: remote job entry: remote job entry: 7: echo: echo: echo: 9 ... RFC 7605: Recommendations on Using Assigned Transport Port Numbers RFC 7605 Recommendations for Transport Port Use August 2015 There are a few good examples of reasons that more directly suggest that not only is a port number assignment not necessary, but it is directly counter-indicated: o Assigned port numbers are not intended to differentiate performance variations within the same service, e.g., high-speed ... Service overview and network port requirements for Windows Although many services may rely on a particular TCP or UDP port, only one service or process at a time can listen on that port. When you use RPC with TCP/IP or with UDP/IP as the transport, incoming ports are frequently dynamically assigned to system services as required. ... To view this organization's list of TCP/IP port assignments, see ... Service Name and Transport Protocol Port Number Registry services that run over transport protocols such as TCP, UDP, DCCP, and. SCTP. Service names are assigned on a first-come, first-served process, as. documented in [RFC6335]. Port numbers are assigned in various ways, based on three ranges: System. Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private. TCP/UDP Ports A port is a communication point where one or more computers in a network talk with each other through a program or software. There are about 0-65535 ports assigned to do specific tasks in a PC. Most ports operate with TCP or UDP protocol. Port numbers are officialy assigned by an organisation called IANA and ports are […] PDF Common Port Assignments Common Port Assignments Table D-1 lists currently assigned Transmission Control Protocol (TCP) port numbers. To the extent possible, the User Datagram Protocol (UDP) uses the same numbers. Table D-1 Currently Assigned TCP and UDP Port Numbers Port Keyword Description 0— Reserved 1-4 — Unassigned 5 RJE Remote job entry 7ECHO Echo 9 DISCARD ... Port Numbers You can lookup our TCP ports database and find details related to assignment Port or Protocol assigned by IANA ... Lookup Port. Port Numbers and Protocols. TCP and UDP are two different protocols that are used for transmitting data over a network. TCP (Transmission Control Protocol) is a connection-oriented protocol that ensures that data is ... IANA Allocation Guidelines for TCP and UDP Port Numbers This document defines the IANA guidelines for registering new port number values for use with the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). It provides clear processes for the TCP and UDP port number registries, important for their long-term management. It updates RFC2780 by replacing Sections 8 and 9.1 of that RFC. A. TCP Table A.1 lists many common ports in use for both the TCP and UDP protocols, under the Port column as T and U, respectively. The most widely used ports are typically found in the range 1 to 1023 and are referred to as the "well-known ports." A large range of port assignments are registered by vendors for specific applications. IANA IANA Internet Assigned Numbers Authority (IANA) The IANA assigns a lot of different numbers (and the like) related to network protocols. Widely known are the well known TCP/UDP port assignments (see PortReference), such as the assignment of TCP port 80 as the standard port for HTTP traffic. In addition to this, the IANA has made a number of other assignments: Well-known UDP port assignments Table 1. Well-known UDP port assignments; Port number Keyword Assigned to Services description; 0 : reserved : 5: rje: remote job entry: remote job entry: 7: echo Service Name and Transport Protocol Port Number Registry services that run over transport protocols such as TCP, UDP, DCCP, and. SCTP. Service names are assigned on a first-come, first-served process, as. documented in [RFC6335]. Port numbers are assigned in various ways, based on three ranges: System. Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private. Adding or Changing TCP/UDP Port Assignments Add a New Port Assignment. Choose Set Initial Decoder Parameters from the Options menu on the Control window. Click the TCP tab (or UDP or IPX for those protocols). Choose the Single Port radio button. Enter the port number in the Port Number box. In the Protocol drop-down list, choose the protocol to traverse to. Click the Add button. essay homework paper phd project resume review speech thesis