Why a DNS Change Cannot Set Up a SOCKS Proxy

Changing a DNS answer changes the address a browser connects to. It does not change the protocol the browser speaks once it gets there.

Visit an ordinary HTTP URL and the browser sends HTTP. Visit an HTTPS URL and it starts TLS for that website. A SOCKS5 server expects its own negotiation first: method selection, any authentication, and a request naming the destination. An unconfigured browser sends none of that.

This explains why a reachable Dante listener can immediately close a connection after a DNS change. The service may be healthy; the incoming bytes belong to the wrong protocol. Moving the listener to port 80 or 443 does not translate those bytes into SOCKS.

Configure a browser's SOCKS interface, such as Firefox's SOCKS settings, or an application-specific proxy setting, so that it performs the handshake and asks the proxy to connect onward. A PAC file can select a supported proxy route for applications that consume it. It is still a separate proxy configuration, not a property of an A or AAAA record.

HTTPS adds another obstacle to the DNS-only idea. The browser continues to expect the identity of the website in the URL. A certificate for the proxy host cannot satisfy that expectation simply because DNS sent the connection there.

Transparent network interception is a different design involving routing and compatible interception software. It cannot be obtained by returning a SOCKS server's address from DNS.