My ADSL and internet service provider, Telefónica España, just installed a network of transparent proxy caches. I suspected this when last week I suddenly lost my ability to immediately see updates to modified websites, and then confirmed with the ip-calculator service.
I called Telefónica to complain and let them know that this causes serious problems for professionals making frequent changes to customer websites. (It’s kinda embarrassing to call a customer and say, “Can you have a look if the change I just made looks ok?”) The response was basically, “Sorry, nothing we can do to help you.” (That was only after I managed to weasel past Line-1 support! “Proxy What? Did you try restarting your computer? Macintosh? Oh, there’s your problem.”)
Any suggested solutions (other than changing providers)?