I ran into this exact issue recently.
To identify which policy was setting the SUS in /Library/Preferences/com.apple.SoftwareUpdate.plist I ran a JSS summary and included Computer Policies. In JSS 9 you can...
1. Gear button in the top right
2. JSS Information on the left
3. JSS Summary
4. Check "Policies" in the Computers section.
5. Check "Software Update Servers" in Computer Management
6. Create at the bottom
Now search that page for "Run SWU" and find which policy is set to true.
The problem for me was to change my "Run Software Update" policy in Self Service.
In Policies > Run Software Update > Software Updates section I changed the "Install Software Updates From" to "Apple's Software Update server".
Since this was changed things are good in my environment.
If you'd like to run a policy to remove that bogus URL the command is...
sudo defaults delete /Library/Preferences/com.apple.SoftwareUpdate CatalogURL
This will set the SUS back to default (Apple's)
Edit: Oh, and for updates we're using Apple's Caching Server. 95% of our environment is on 10.8 or 10.9 at this point so it utilizes it easily. We also have a large fiber connection so bandwidth isn't much of a concern.
Just out of curiosity do you have your JSS pushing out a setting for your ASUS location? Could you have turned it on with out actually setting an address?
@monogrant: thanks for this great tip to identify policy settings! I used your command to reset the default server and it worked better than what I tried.
@easyedc We used to have our own update server but had to revert back to Apple for the moment for reasons too long to explain. I think some of the old settings got stuck when we upgraded. Resetting to Apple's default and playing with the settings "on/off" seems to have worked wonders. We're back on schedule. :)
Thanks
Had a similar issue where the user's machine was defaulting the SUS to an old IP address of an internal server. A reboot was not performing the update to the latest internal SUS servers. We also tried full removal of JAMF framework and re-enroll machine but no luck.
What solved this was that the user was logged into the Apple Store with their Apple ID. When they logged out and we performed the full removal of JAMF framework and enrollment then it got updated. We are going to try with a second user to sign out of Apple Store to see if the update can happen from a simple reboot.