Proxychains DNS: Why Hostnames Get Synthetic IP Addresses

A program under proxychains resolves a normal hostname to an unfamiliar address range. That address may be a bookkeeping value inside the wrapper rather than a DNS answer from the internet.

In its proxy-DNS mode, proxychains-ng can remember a hostname, return a synthetic address to the application, and later translate that value back into the hostname when the intercepted connection is opened through a proxy.

The placeholder is not the exit IP

The sample configuration documents proxy_dns and remote_dns_subnet. The reserved mapping range is configurable. It is not an address you should expect to ping or publish as the proxy's public source.

This relies on the relevant name lookup and connection calls being intercepted within the intended process. A program that performs its own DNS over another mechanism, stores the placeholder for later unrelated use, or bypasses the hooked socket path can behave differently.

That limitation explains why a synthetic address in a log is not, by itself, proof that the whole application is using remote DNS correctly. Likewise, a separate DNS utility outside the wrapped process does not test the application's mapped connection.

Distinguish the application's placeholder, the real destination address chosen on the proxy side, and the public exit observed by the website. They serve different jobs and need not match.

When debugging, keep the hostname available in your notes and identify the exact wrapped process and configuration. Replacing a suspicious-looking placeholder manually can discard the mapping the wrapper needed to recover that hostname, turning an understandable indirection into a connection to the wrong destination.