Remote DNS analysis of SOCKS agents

Comrades who often use the SOCKS proxy server will find a phenomenon, even if the SOCKS proxy server settings are correct, some websites are still unable to access, such as a famous Weibo website. Its general reasons are DNS Pollution (DNS Cache Poisoning).

Fortunately, the SOCKS 5 protocol adds support for the UDP packet. The DNS query is transmitted through UDP, so we can make DNS query packets also take the SOCKS 5 agent for remote DNS lookups. The DNS service is an Internet’s basic service, requiring DNS parsing to be as fast as possible, so browser does not use remote DNS parsing by default. In the current common browser, it seems that only Firefox supports an optional remote DNS resolution, see here.

I didn’t find the method of IE and Chrome support remote DNS parsing. From discussion, it seems that it is not supported. Opera does not have SOCKS proxy support.

Even Firefox, support for remote DNS parsing is also some problems. My experience is: Firefox only supports remote DNS resolution only when writing SOCKS V5 proxy settings inside, when using the Auto Agent Settings Script (.pac), Firefox will not perform even if the SOCKS agent is returned. Far DNS parsing.

Conclusion Yes, if you want a remote DNS resolution, you can only switch the SOCKS agent to use the automatic agent configuration script.