Originally from ticket #6501.
I can't get Apple iOS updates over the Guest WiFi network. I do not know if this is normal behavior or if Apple is telling the Guest clients to use the new caching server. If this is the case perhaps they can't reach the caching server from Guest WiFi. I was able to get the iOS updates on CASecure.
Thanks!
CAGuest only allows traffic over ports 80 and 443 (only web browsers). It appears as though port 8088 may also be required for software updates.
http://support.apple.com/kb/ts1629
I don't know if the Mac server mentioned in that article is what Apple is using (on Apple's side or the caching server's side) or if that has been co-opted by iOS as well, but it's worth checking in to.
For clients who have @calarts.edu or @alum.calarts.edu addresses we strongly recommend people use CASecure, which does not have the limitation that CAGuest does. Updates and such will work exactly as expected on CASecure!