OS X Server 10.8

i followed the infos from http://support.apple.com/kb/HT4069 but this is not working like this.

Has someone a solution.

The http://su.example.com:8088/index.sucatalog link is not working in OS X Server 10.8

If i enter http://su.example.com:8088/catalogs.sucatalog the link is working from client.

But if i read the CatalogURL with

defaults read /Library/Preferences/com.apple.SoftwareUpdate CatalogURL

i get this error and software update is not working

The domain/default pair of (/Library/Preferences/com.apple.SoftwareUpdate, CatalogURL) does not exist