MORE INFORMATION
The following excerpt from IIS 5.0 Help (the path to this information is Contents, Administration, Server Administration, Web and FTP sites, and Downlevel Site Administration) describes a problem concerning application mappings when you are administering IIS 5.0 from the IIS 4.0 Microsoft Management Console (MMC) snap-in:
Important! The column entitled Verbs in the App Mappings property sheet lists the HTTP verbs that will be run by an application. In IIS 4.0, this column, entitled Exclusions, listed the HTTP verbs that would not be run by an application. If you perform remote administration tasks between computers running IIS 4.0 and IIS 5.0, this column will be incorrectly labeled.
For more information on application mappings, see Setting Application Mappings.
This problem can actually occur in both directions (in other words, the problem can happen when administering IIS 5.0 from a Windows NT 4.0/IIS 4.0 server and vice versa).
The following is a detailed description of the problem: If an administrator double-clicks on a specific application mapping in the IIS 4.0 Internet Service Manager's
Application Configuration dialog box on the
App Mappings tab, this brings up the
Add/Edit application extension mapping form. The part of this form that concerns HTTP verbs is titled "Method Exclusions". On IIS 4.0, the default behavior for this form is to exclude only the HTTP verbs that you do not want to allow for a given application mapping (from example, "exclude PUT, DELETE from .ASP").
This behavior was changed in IIS 5.0. The corresponding form is now titled "Limit to:" and you type in the HTTP verbs you want to
include.
For example, on a Windows 2000 Server, if you use the IIS 5.0 Internet Service manager to locally edit the application mapping for the .asp extension, the default behavior for the HTTP verbs is "Limit to: GET, HEAD, POST, TRACE". This configuration information is then written to the metabase under the
ScriptMaps key as:
.asp,C:\WINNT\System32\inetsrv\asp.dll,1,GET,HEAD,POST,TRACE
If this same procedure is performed from a Windows NT 4.0/IIS 4.0 Internet Service Manager while you are remotely connected to a Windows 2000/IIS 5.0 server, the IIS 4.0 Internet Service Manager will read this information from the metabase and display "GET, HEAD, POST, TRACE" in the form field as "method exclusions", even though these are really method
inclusions. If the IIS 4.0 administrator notices this and changes these values to reflect the proper default method exclusions for IIS 4.0 ("PUT, DELETE"), these values will be written back to the IIS 5.0 servers metabase and the ScriptMaps key will appear as:
.asp,C:\WINNT\System32\inetsrv\asp.dll,1,PUT,DELETE
IIS 5.0 will then only allow the HTTP verbs PUT and DELETE to be sent to ASP pages, which causes the Web application to fail.