ginuerzh/gost · error

bind: peer connect failure

Error message

bind: peer connect failure

What it means

The SOCKS5 BIND handshake completed its first reply, but the second reply (sent when the peer connects) reports a non-Succeeded reply code (rep.Rep != gosocks5.Succeeded), meaning the remote peer's inbound connection to the server's bound port failed on the proxy side. This library turns any failed BIND reply code into this fixed error.

Solutions

1. Check the proxy server logs for the actual SOCKS5 reply code (e.g. connection refused, host unreachable)
2. Ensure the peer can reach the proxy's bound address/port (firewall/NAT rules)
3. Confirm the proxy server supports the BIND command at all — many modern proxies only support CONNECT
4. Prefer CONNECT-based dialing unless you specifically need reverse (BIND) connections

// ensure the proxy supports BIND before relying on it
// e.g. probe server capabilities or check server docs; no client-side API check exists
if !proxySupportsBind(proxyAddr) { useConnectDialer() }

c, err := bindDialer.Bind(ctx, addr)
if err != nil {
    if err.Error() == "bind: peer connect failure" {
        c, err = connectDialer.Connect(ctx, addr) // fallback to CONNECT
    }
    if err != nil { return err }
}

When it happens

Trigger: Using a SOCKS5 BIND connection when the server's second reply carries a failure code — e.g. connection refused/blocked between the peer and the proxy's bound port, or the bind request was rejected at the second stage.

Common situations: Peer is behind a firewall and cannot reach the proxy's bind port; the proxy does not truly support BIND; NAT prevents the inbound connection; client is not reachable from the proxy network.

Related errors

• Bind on failure
• bind: read reply
• SOCKS5 bind on failure
• peer connect failure
• unsupported

AI-assisted analysis of ginuerzh/gost@a33fdbf4c9 (2026-09-02). Data as JSON: /api/errors/8e5021bfd446da82. Report an issue: GitHub.

Appendix: source

Thrown at socks.go:2001

}

// Handshake waits for a peer to connect to the bind port.
func (c *socks5BindConn) Handshake() (err error) {
	c.handshakeMux.Lock()
	defer c.handshakeMux.Unlock()

	if c.handshaked {
		return nil
	}

	c.handshaked = true

	rep, err := gosocks5.ReadReply(c.Conn)
	if err != nil {
		return fmt.Errorf("bind: read reply %v", err)
	}
	if rep.Rep != gosocks5.Succeeded {
		return fmt.Errorf("bind: peer connect failure")
	}
	c.raddr, err = net.ResolveTCPAddr("tcp", rep.Addr.String())
	return
}

func (c *socks5BindConn) Read(b []byte) (n int, err error) {
	if err = c.Handshake(); err != nil {
		return
	}
	return c.Conn.Read(b)
}

func (c *socks5BindConn) Write(b []byte) (n int, err error) {
	if err = c.Handshake(); err != nil {
		return
	}
	return c.Conn.Write(b)
}

View on GitHub (pinned to a33fdbf4c9)