Has Ap­ple blocked us?

Mac Format - - APPLE TALK -

I was in­ter­ested to see your re­sponse to John R Gor­don’s prob­lem ( MF282) with what had been his daugh­ter’s Mac­Book. My hus­band tried to use In­ter­net Re­cov­ery on his Mac­Book Air, to take it back from Yosemite to its orig­i­nal Moun­tain Lion in­stal­la­tion. He was un­able to do so and even con­tacted our ISP, Zen In­ter­net, who could only con­clude that Ap­ple must have ‘blocked’ the UK from this fa­cil­ity. Could you please ex­plain how In­ter­net Re­cov­ery should work? Su­san Plat­ter Macs have two ways to re­in­stall the op­er­at­ing sys­tem. Re­cov­ery mode (restart with ç+r held down) will re­store from the re­cov­ery par­ti­tion on their in­ter­nal stor­age, which will con­tain the most re­cent ver­sion of OS X in­stalled on your Mac. The other way is In­ter­net Re­cov­ery, which down­loads the orig­i­nal OS ver­sion that shipped with your Mac. To use this, restart with ç+å+r.

Now, if that doesn’t work, it cer­tainly isn’t be­cause Ap­ple is block­ing the ser­vice in the UK – that would make no sense at all. But your ISP or the fire­wall on your router may be do­ing so. In­ter­net Re­cov­ery needs to be able to con­tact two spe­cific server names. You can check this is work­ing from Net­work Util­ity (use Spot­light to search for it, be­cause it’s not in the Ap­pli­ca­tions folder). En­ter os­re­cov­ery.ap­ple.com as the ad­dress and get it to scan ports 80 and 443. Net­work Util­ity only lets you scan con­tigu­ous ranges of port num­bers, so you will have to run one scan from 80 to 80, and an­other from 443 to 443. If you try scan­ning from 80 to 443 in one go, it will take ages while it waits for all the in­valid ports to time out. If the ports open cor­rectly, you will see a mes­sage say­ing “Open TCP Port: 80 http” – or “https”, in the case of port 443. If the port can’t be opened, there will be a long pause and then it will sim­ply say “Port Scan has com­pleted”. Do the same thing for os­cdn. ap­ple.com. If ei­ther port on ei­ther server does not re­spond, then a fire­wall or proxy server some­where in your in­ter­net con­nec­tion is block­ing ac­cess to the nec­es­sary servers, or your DNS server isn’t gen­er­at­ing the right in­ter­net ad­dress for the server names. This sounds com­pli­cated, but this test is just to en­able you to show your ISP that the prob­lem is its to solve.

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