Errors like the following seen on Agent logs when trying to post data to PostEvent.asp:
<![CDATA[PostFile to 'HTTP://'NS Server' /ALTIRIS/NS/Agent/PostEvent.asp' failed: HTTP error: 405 Method Not Allowed (-2147209951)]]></event>
8.x
ASP Script Mapping was missing from the default website.
To add or modify the .asp extension, go to IIS Settings > Right-click on Default Web site, select Properties > Select Home Directory Tab > Click the Configuration button.
If the .asp extension is there, make sure it has GET, HEAD, POST, and DEBUG verbs entered.
If it is missing, Add the .ASP Extension Script Mapping with Executable path of c:\winnt\system32\inetsrv\asp.dll, and the following verbs (GET HEAD POST DEBUG)
After making this modification, the Agents were able to send Inventory to the NS without error.