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<runtime> Element

Contains information about assembly binding and garbage collection.

<configuration> Element
  <runtime> Element


Attributes and Elements

The following sections describe attributes, child elements, and parent elements.



Child Elements




Specifies that the Windows identity always flows across asynchronous points, regardless of how impersonation was performed.

<assemblyBinding> Element for <runtime>

Contains information about assembly version redirection and the locations of assemblies.

<bypassTrustedAppStrongNames> Element

Specifies whether strong name verification for trusted assemblies should be bypassed.


Specifies whether the runtime searches for assemblies in directories specified by the DEVPATH environment variable.


Specifies whether the caching of binding failures, which is the default behavior in the .NET Framework version 2.0, is disabled.


Specifies whether to enforce a computer configuration requirement that cryptographic algorithms must comply with the Federal Information Processing Standards (FIPS).


Specifies whether the common language runtime runs garbage collection concurrently.


Specifies whether the common language runtime runs server garbage collection.


Specifies that the Windows identity does not flow across asynchronous points, regardless of the flow settings for the execution context on the current thread.


Specifies whether the runtime uses legacy code access security (CAS) policy.

Parent Elements




The root element in every configuration file used by the common language runtime and .NET Framework applications.


In the .NET Framework version 2.0, the impersonated identity flows across asynchronous points within an application domain. In the .NET Framework version 2.0, you can enable or disable the flow of impersonation across asynchronous points by properly configuring the runtime element in the machine.config file or in the application configuration file. For ASP.NET, the impersonation flow can be configured in the aspnet.config file found in the <Windows Folder>\Microsoft.NET\Framework\vx.x.xxxx directory.

By default ASP.NET disables the impersonation flow in aspnet.config file by using the following configuration settings:

      <legacyImpersonationPolicy enabled="true"/>
      <alwaysFlowImpersonationPolicy enabled="false"/>

In ASP.NET, if you want to allow the flow of impersonation instead, you must explicitly use the following configuration settings:

      <legacyImpersonationPolicy enabled="false"/>
      <alwaysFlowImpersonationPolicy enabled="true"/>

For more information, see <legacyImpersonationPolicy> Element and <alwaysFlowImpersonationPolicy> Element.


The following example shows how to redirect one assembly version to another.

      <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
            <assemblyIdentity name="myAssembly"
                              culture="neutral" />
             <bindingRedirect oldVersion=""

See Also


How to: Disable Concurrent Garbage Collection


Redirecting Assembly Versions


Runtime Settings Schema

Other Resources

Configuration File Schema for the .NET Framework

Change History




May 2011

Added missing <enforceFIPSPolicy> element.

Customer feedback.