VSDISCO files are DISCO files that support dynamic discovery of Web services.
If you place the following VSDISCO file in a directory on your Web server,
for example, it returns references to all ASMX and DISCO files in the host
directory and any subdirectories not noted in <exclude> elements:
<?xml version="1.0" ?>
<dynamicDiscovery
xmlns="urn:schemas-dynamicdiscovery:disco.2000-03-17">
<exclude path="_vti_cnf" />
<exclude path="_vti_pvt" />
<exclude path="_vti_log" />
<exclude path="_vti_script" />
<exclude path="_vti_txt" />
</dynamicDiscovery>
How does dynamic discovery work? ASP.NET maps the file name extension VSDISCO
to an HTTP handler that scans the host directory and subdirectories for ASMX
and DISCO files and returns a dynamically generated DISCO document. A client
who requests a VSDISCO file gets back what appears to be a static DISCO document.
Note that VSDISCO files are disabled in the release version of ASP.NET. You
can reenable them by uncommenting the line in the <httpHandlers> section
of Machine.config that maps *.vsdisco to System.Web.Services.Discovery.DiscoveryRequestHandler and
granting the ASPNET user account permission to read the IIS metabase. However,
Microsoft is actively discouraging the use of VSDISCO files because they could
represent a threat to Web server security.
Siva