Runtime configuration options for networking

HTTP/2 protocol

• Configures whether support for the HTTP/2 protocol is enabled.
• If you omit this setting, support for the HTTP/2 protocol is enabled. This is equivalent to setting the value to true.

	Setting name	Values
runtimeconfig.json	System.Net.Http.SocketsHttpHandler.Http2Support	false - disabled true - enabled
Environment variable	DOTNET_SYSTEM_NET_HTTP_SOCKETSHTTPHANDLER_HTTP2SUPPORT	0 - disabled 1 - enabled

This configuration setting doesn't have a specific MSBuild property. However, you can add a RuntimeHostConfigurationOption MSBuild item instead. Use the runtimeconfig.json setting name as the value of the Include attribute. For an example, see MSBuild properties.

SPN creation in HttpClient (.NET 6 and later)

• Impacts generation of service principal names (SPN) for Kerberos and NTLM authentication when Host header is missing and target is not running on default port.
• .NET 6 and later versions don't include the port in the SPN, but the behavior is configurable.

	Setting name	Values
runtimeconfig.json	System.Net.Http.UsePortInSpn	true - includes port number in SPN, for example, HTTP/host:port false - does not include port in SPN, for example, HTTP/host
Environment variable	DOTNET_SYSTEM_NET_HTTP_USEPORTINSPN	1 - includes port number in SPN, for example, HTTP/host:port 0 - does not include port in SPN, for example, HTTP/host

This configuration setting doesn't have a specific MSBuild property. However, you can add a RuntimeHostConfigurationOption MSBuild item instead. Use the runtimeconfig.json setting name as the value of the Include attribute. For an example, see MSBuild properties.