When using a load balancer to distribute client requests across multiple web front ends, the Explorer View functionality may fail to operate properly. The failure may be represented to the client as repeated prompts for authentication, or the client may receive a generic "Page cannot be displayed" error message.
This problem may appear inconsistent across clients depending on the configuration of the client computer. This is because the Explorer View feature relies on IE Web Folder Behaviors to provide it’s functionality. The IE Web Folders Behavior can leverage either of two possible protocols to produce the Explorer View experience:
The Windows Web Client Service which uses the standard WebDAV protocol.
Clients which do not have the Web Extender Client components installed will experience this problem, while clients that do have these components installed may be immune. The Web Extender Client components were originally shipped as part of the Office suite and within 32-bit versions of the Microsoft Windows operating systems. Starting with Windows Vista, these components were no longer provided with the operating system.
The SharePoint Explorer View feature requires certain standard WebDAV verbs to provide its expected functionality. Any load balancer need to be configured to forward these verbs to the SharePoint Web Front End servers in order for the Explorer View feature to work correctly.
Configure the load balancer to forward all of the following verbs:
Microsoft Office SharePoint Portal Server 2003, Microsoft Windows SharePoint Services 2.0, Microsoft Windows SharePoint Services 3.0, Microsoft SharePoint Foundation 2010, Microsoft SharePoint Server 2010, Microsoft Office SharePoint Server 2007