Event ID 5178 — IIS Protocol Adapter Configuration

Event ID 5178 — IIS Protocol Adapter Configuration

Updated: March 24, 2009

Applies To: Windows Server 2008 R2

The Windows Process Activation Service (WAS) reads the configuration for a protocol adapter upon startup. Changes to protocol adapter configuration take effect only when the adapter connects with WAS. If errors occur when WAS is using protocol adapter specific configuration, configuration information for the adapter may not be available.

Event Details

Product: Internet Information Services
ID: 5178
Source: Microsoft-Windows-WAS
Version: 7.5
Message: An attempt was made to register protocol ‘%1’, however protocol ‘%1’ is all ready being handled by another listener adapter. Therefore the registration was rejected. The data field contains the error number.

Delete a duplicate listener adapter protocol

The listenerAdapters section in the ApplicationHost.config file defines the protocols with which the Windows Process Activation Service (WAS) binds.

Each listener adapter has a name attribute that contains the name of the protocol that the listener adapter processes. Only one listener adapter can be defined for each protocol, or WAS will be unable to process requests for the protocol that has the duplicate definition.

To fix this issue, find the duplicate protocol in the ApplicationHost.config configuration file and remove it.

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To remove the duplicate listener adapter protocol:

  1. Open an elevated Command Prompt window. Click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type cd %Windir%\system32\inetsrv\config
  3. Type notepad ApplicationHost.config
  4. In notepad, search for the listenerAdapters section under system.applicationHost.
  5. Remove the duplicate protocol.
  6. Save the applicationHost.config file, and exit notepad.

For more information about the configuration of the listenerAdapters section, see IIS 7.0: add Element for listenerAdapters (IIS Settings Schema).


You can use an Internet browser to verify that a protocol adapter is functional by following these steps:

  1. Select a Web site or application that is configured to respond to the protocol you want to verify.
  2. In the address bar of your browser, type a protocol-specific request to the Web site or applications that you chose in step 1. For example, http://servername/default.htm
  3. If the protocol adapter is working, your browser client should display the expected output page.

Note: If the protocol adapter is from a third party, refer to the documentation for the adapter. The documentation may have  specific steps that explain how to verify the state of the service or process that hosts the protocol adapter.

Related Management Information

IIS Protocol Adapter Configuration

Internet Information Services (IIS) 7.5


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