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Remote Debugger Port Assignments

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The Visual Studio Remote Debugger can run as an application or as a background service. When it runs as an application, it uses a port that is assigned by default as follows:

  • Visual Studio 2022: 4026

  • Visual Studio 2019: 4024

  • Visual Studio 2017: 4022

  • Visual Studio 2015: 4020

  • Visual Studio 2013: 4018

  • Visual Studio 2012: 4016

In other words, the number of the port assigned to the remote debugger is incremented by 2 for each release. You can set a different port number if you like. We will explain how to set port numbers in a later section.

The Remote Debugger Port on 32-bit Operating Systems

TCP 4026 (in Visual Studio 2022) is the main port, and is required for all scenarios excluding Azure App Service. You can configure this from either the command line or the remote debugger window.

TCP 4024 (in Visual Studio 2019) is the main port, and is required for all scenarios. You can configure this from either the command line or the remote debugger window.

In the remote debugger window, click Tools > Options, and set the TCP/IP port number.

On the command line, start the remote debugger with the /port switch: msvsmon /port <port number>.

You can find all the remote debugger command line switches in the remote debugging help (press F1 or click Help > Usage in the remote debugger window).

The Remote Debugger Port on 64-bit Operating Systems

When the 64-bit version of the remote debugger is started, it uses the main port (4026) by default. If you debug a 32-bit process, the 64-bit version of the remote debugger starts a 32-bit version of the remote debugger on port 4025 in most cases. If you run the 32-bit remote debugger, it uses 4026, and 4025 is not used. The exception to this if Remote Tools for Visual Studio 2022 version 17.2 or newer is installed, and the Remote Debugger Configuration Wizard is used to start the remote debugger as a service, then the default 32-bit debugging port will be 4040 instead of 4025.

When the 64-bit version of the remote debugger is started, it uses the main port (4024) by default. If you debug a 32-bit process, the 64-bit version of the remote debugger starts a 32-bit version of the remote debugger on port 4025 (the main port number incremented by 1). If you run the 32-bit remote debugger, it uses 4024, and 4025 is not used.

This port is configurable from the command line: Msvsmon /wow64port <port number>.

Remote Debugger Ports on Microsoft Azure App Service

Remote debugger ports are configurable. Currently, Azure App Service does not use the default ports associated with your version of Visual Studio. Azure App Service uses port 4024 for the remote debugger.

The Discovery Port

UDP 3702 is used for finding running instances of the remote debugger on the network (for example, the Find dialog in the Attach to Process dialog). It is used only for discovering a machine running the remote debugger, so it is optional if you have some other way of knowing the machine name or IP address of the target computer. This is a standard port for discovery, so the port number cannot be configured.

If you do not want to enable discovery, you can start msvsmon from the command line with discovery disabled: Msvsmon /nodiscovery.

See also