Resposta do link Chopper3 :
Uma regra de firewall no Sonicwall causou o problema.
Then I thought to look at my Sonicwall NSA 2400; we have the Application Control enabled, and this has been known to cause strange network connectivity issues even when not expected so I’ve just by default started checking here.
Unsurprisingly this turned out to be the problem. The strange thing is, the AppControl rule that was blocking the traffic isn’t visible in the list of applications; only through the logging did I find it.
Turns out the rule “Non-SSL Traffic over SSL port” is blocking this Windows Update traffic. Setting the Block option to Disabled for this rule allows Windows Update to work properly.