When choosing a proxy IP, it's important to consider its quality and reliability. High-quality proxy IP providers typically offer advanced features such as automatic IP switching, high-speed connections, better anonymity, and more stable service. They may also provide helpful tools such as IP speed measurement tools, proxy IP pools, and API interfaces to help users manage and use proxy IP. Additionally, high-quality proxy IP providers usually offer professional and timely customer service support.

One of the main reasons for a proxy IP to fail is an unstable network connection. This can cause the link to drop or slow down, making it difficult for the client to connect to the proxy server. Additionally, if the proxy IP address is blocked, it cannot be used. Another possible reason for failure is a problem with the server configuration of the proxy IP, which can cause service instability.

When a proxy IP fails, it can cause a lot of inconvenience as the client cannot connect to the proxy server, making the webpage inaccessible. To solve this problem, it's important to use a valid and high-quality proxy IP. The choice of proxy IP provider should be based on its ability to provide stable and fast network connections, professional customer service support, and complete functions.

High-quality proxy IPs usually require authorization to use. Two common authorization methods are binding IP allowlist and account password authorization. With binding IP allowlist authorization, if the terminal IP is not fixed, permission to bind the IP allowlist may fail. In this case, after setting the proxy IP, the login window for "username and password" will pop up, but even after entering the correct information, the webpage may still not be accessible. With account password authorization, the correct username and password must be entered. If the input is incorrect, access to the webpage will be denied.

It's important to note that if an IP is restricted,