XTLS/Xray-core · error

failed to establish connection to server

Error message

failed to establish connection to server

What it means

Error "failed to establish connection to server" thrown in XTLS/Xray-core.

Source

Thrown at proxy/socks/client.go:108

		Port:    destination.Port,
	}

	if destination.Network == net.Network_UDP {
		request.Command = protocol.RequestCommandUDP
	}

	user := server.User
	if user != nil {
		request.User = user
		p = c.policyManager.ForLevel(user.Level)
	}

	if err := conn.SetDeadline(time.Now().Add(p.Timeouts.Handshake)); err != nil {
		errors.LogInfoInner(ctx, err, "failed to set deadline for handshake")
	}
	udpRequest, err := ClientHandshake(request, conn, conn)
	if err != nil {
		return errors.New("failed to establish connection to server").AtWarning().Base(err)
	}
	if udpRequest != nil {
		if udpRequest.Address == net.AnyIP || udpRequest.Address == net.AnyIPv6 {
			udpRequest.Address = dest.Address
		}
	}

	if err := conn.SetDeadline(time.Time{}); err != nil {
		errors.LogInfoInner(ctx, err, "failed to clear deadline after handshake")
	}

	var newCtx context.Context
	var newCancel context.CancelFunc
	if session.TimeoutOnlyFromContext(ctx) {
		newCtx, newCancel = context.WithCancel(context.Background())
	}

	ctx, cancel := context.WithCancel(ctx)

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/socks/client.go:108 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/fe20c960e12098d4. Report an issue: GitHub.