Proxies are also fuzzy. I assume you're referring to e.g. a 407 or 511 error? Many times they're handled by something between you and the network library, oft

Proxies are also fuzzy. I assume you're referring to e.g. a 407 or 511 error? Many times they're handled by something between you and the network library, often the operating system. Sometimes they're not handled at all at the system level (hooray, Android (until recent versions)!), so if you didn't put a proxy in there, you don't have one. VPNs can also exist, but they sometimes send custom error status codes[1]. How do you handle those? Retry if `code % 3 == 1`? Will your program even be informed if the VPN connection is restored, or will you have to just blindly retry until it works? [1]: http://compnetworking.about.com/od/vpnsetup/tp/common-vpn-error-codes-explained.htm http://compnetworking.about.com/od/vpnsetup/tp/common-vpn-er...