An HTTP proxy cannot be used for all traffic; only Layer 7 (HTTP/HTTPS) protocols can be proxied through this mode. For the SOCKS5 mode, you can proxy all Layer 4 (e.g. TCP/UDP) traffic through it regardless of the protocols in use. It’s just like running TOR, which uses the same SOCKS5 technology.
- Now, you can use a SOCKS client like socksify on your LAN hosts to tunnel traffic through the OpenWRT SOCKS5 proxy.
- If however, you not want to install any client software on your LAN hosts, you should do some more configurations on the OpenWRT itself to intercept, and redirect all inbound traffic to the proxy.
Something like this might help, although it is more advanced and more than you need:
Note! SOCKS always slow down the traffic!