IPv4 and IPv6 Proxies: Which Connection Needs Support?
The client-to-proxy connection and the proxy-to-website connection can use different address families. Check both before choosing an endpoint.
An IPv6 proxy listener needs an IPv6 route from your client. Its outbound connection to a website can still use IPv4. Conversely, an IPv4 listener can reach an IPv6 destination if the proxy has the necessary support and route.
| Connection | Required support |
|---|---|
| Client → proxy | A route to the endpoint's address and a reachable listening service. |
| Proxy → destination | A suitable destination address, resolver, outbound route and access policy at the proxy. |
Format an IPv6 literal with brackets in a full proxy URL:
http://[2001:db8::10]:8080Replace the documentation address with the real endpoint. Separate host/port fields may expect the unbracketed address; follow the application's format. Correct syntax cannot create a missing IPv6 route, so compare your network's IPv6 status or another IPv6 destination before blaming the listener.
Which side chooses the destination address?
A hostname-based CONNECT request leaves the destination connection to the proxy. SOCKS5 can carry an IPv4 address, IPv6 address or domain name, according to the client's mode. Forcing a client-side address-family option does not necessarily constrain a hostname resolved remotely; identify which connection that option affects.
An IP checker reporting IPv4 after you selected an IPv6 listener is therefore possible without a second client connection. First establish whether it reports its TCP peer, an application header or another browser request. Plain HTTP forwarding can add client-address information; an ordinary CONNECT relay cannot insert a header into encrypted destination HTTP. Forwarded information needs a trust policy and is not by itself proof of another network connection.
Record endpoint, target, protocol and first failure. Failure to reach the listener differs from its reply that the destination is unreachable. The collector behind the ProxyHub proxy list currently accepts IPv4 records; these IPv6 examples describe general behavior, not a current IPv6 list filter.