what does Http 407 proxy athentication mean?

Answer 1

Your Web server thinks that the HTTP data stream sent from the client (e.g. your Web browser or our CheckUpDown robot) was correct, but access to the URL resource requires the prior use of a proxy server that needs some authentication which has not been provided. This typically means you must log in (enter user ID and password) with the proxy server first.

A 407 error detected via a Web browser can often be resolved by navigating to the URL in a slightly different way e.g. accessing another URL for the proxy server first. Your ISP should be able to explain the role of the proxy server in their security setup and how you should use it.