3.3. The Former use of the Microsoft Loopback Adapter by the OpenAFS Client Service

This section is preserved for those sites that may want to manually configure the OpenAFS Client Service to run as an SMB Gateway to AFS instead of using the native IFS file system redirector driver. When the IFS driver is active, the Microsoft Loopback Adapter is ignored. The OpenAFS 1.7.x installer will not install a Microsoft Loopback Adapter by default nor will it remove one if already present on the machine.

The Microsoft Loopback Adapter (MLA) is installed with a name "AFS" and a pre-assigned IP address of The MLA is bound to the "Client for Microsoft Networks" service and not bound to the "File and Printer Sharing for Microsoft Networks" service. If the MLA is unbound to "Client Microsoft Networks", the OpenAFS Client Service will become inaccessible when the machine is disconnected from the network. If the MLA is bound to "File and Printer Sharing ..." there will be a service type collision between the "AFS" SMB Service and the local machine's File Sharing Service. This will result in the OpenAFS client service becoming inaccessible and the "NET VIEW \\AFS" command will return a "System Error 52" message. To correct the problem:

  • stop the AFS Client Service

  • bind the "Client for Microsoft Networks" to the MLA

  • unbind "File and Printer Sharing for Microsoft Networks" from the MLA

  • disable and then re-enable the MLA

  • start the AFS Client Service

When the MLA is not installed the NETBIOS name published by the OpenAFS SMB server must be unique in order to avoid name conflicts on public network. The unique name will take the form "MACHINE-AFS". One of the benefits of using the MLA is that the NETBIOS name does not have to be published on any adapter other than the MLA. Therefore the chosen name is no longer required to be globally unique. Instead the NETBIOS name associated with the AFS Client Service is simply "AFS" and portable UNC paths of the form \\AFS\cellname\path can now be used on all machines.