Currently our Snow Leopard and Lion clients are no longer receiving Apple Software Updates through the policy in JAMF (up-to-date now with 8.6). They all report the error "NSURLErrorDomain error -1100". If you manually run Software Updates from the GUI they download and install fine so the server itself seems to be okay. We have an internal Mac OS X server publishing the updates running Mac OS X 10.6.8 Server. I would assume the solution will involve the server or JAMF since clients with 10.6.8, 10.7.2, 10.7.3 and 10.7.4 are all affected including newly imaged workstations. (I did a search for this error here and found an older discussion but the server was reporting that same error and it was resolved with the update to 10.6.3 so this is probably different.)
-Doug
