When using an IPv6 proxy with the SOCKS5 protocol, you may occasionally encounter connection issues due to how DNS resolution is handled. This guide explains how to properly configure SOCKS5 connections and how to fix the most common problem using SOCKS5H.
When Should You Use SOCKS5H Instead of SOCKS5?
In IPv6 environments, the operating system might not resolve domain names to IPv6 addresses by default. This causes issues when connecting via SOCKS5 using a domain (like cheaper-pong.proxycheap.io). If DNS resolution fails locally, the connection will break even if the proxy is valid.
🔧 Recommended Setup (with curl)
❌ Failing Example (due to local DNS resolution):
curl -6 -x socks5://user:password@1.2.3.4:12345 http://cheaper-pong.proxycheap.io
🛠️ Working Example (uses proxy DNS via socks5h):
curl -6 -x socks5h://user:password@1.2.3.4:12345 http://cheaper-pong.proxycheap.io