When a SOCKS5 client receives a domain name, it can either resolve the domain locally or send the hostname to the proxy for resolution. For IPv6-only proxy connections, proxy-side DNS resolution is often the safer option because the proxy can select an IPv6 destination address.

Test with cURL

Replace the placeholders with the details shown in your Proxy-Cheap dashboard:

curl -v --proxy socks5h://HOST:PORT --proxy-user 'USERNAME:PASSWORD' https://api64.ipify.org

A successful request should return an IPv6 address. In cURL, socks5h tells the proxy to resolve the destination hostname. The socks5 scheme resolves the hostname locally.

You normally do not need the -6 flag in this command. That flag can also affect how cURL resolves the proxy host and can cause problems when the proxy endpoint itself is reached over IPv4.

If the request fails

• Confirm the hostname, port, username, password, and protocol shown in the dashboard.
• Make sure the destination supports IPv6. An IPv6-only proxy cannot reach an IPv4-only destination.

• If the proxy endpoint itself is a literal IPv6 address, place it in square brackets:
   

  socks5h://[IPv6_ADDRESS]:PORT.

• Check whether your application supports proxy-side DNS. It may call the option SOCKS5H, remote DNS, or proxy DNS.