EOPNOTSUPP      = syscall.Errno(0x5f)
	EOVERFLOW       = syscall.Errno(0x4b)
	EOWNERDEAD      = syscall.Errno(0x82)
	EPFNOSUPPORT    = syscall.Errno(0x60)
	EPROTO          = syscall.Errno(0x47)
	EPROTONOSUPPORT = syscall.Errno(0x5d)
	EPROTOTYPE      = syscall.Errno(0x5b)
	EREMCHG         = syscall.Errno(0x4e)
	EREMOTE         = syscall.Errno(0x42)
	EREMOTEIO       = syscall.Errno(0x79)
	ERESTART        = syscall.Errno(0x55)

	EOVERFLOW       = syscall.Errno(0x5c)
	EOWNERDEAD      = syscall.Errno(0x84)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPROCLIM        = syscall.Errno(0x43)
	EPROTO          = syscall.Errno(0x56)
	EPROTONOSUPPORT = syscall.Errno(0x2b)
	EPROTOTYPE      = syscall.Errno(0x29)
	EREMCHG         = syscall.Errno(0x59)
	EREMOTE         = syscall.Errno(0x47)
	EREMOTEIO       = syscall.Errno(0x79)
	ERESTART        = syscall.Errno(0x74)

	EOPNOTSUPP      = syscall.Errno(0x5f)
	EOVERFLOW       = syscall.Errno(0x4b)
	EOWNERDEAD      = syscall.Errno(0x82)
	EPFNOSUPPORT    = syscall.Errno(0x60)
	EPROTO          = syscall.Errno(0x47)
	EPROTONOSUPPORT = syscall.Errno(0x5d)
	EPROTOTYPE      = syscall.Errno(0x5b)
	EREMCHG         = syscall.Errno(0x4e)
	EREMOTE         = syscall.Errno(0x42)
	EREMOTEIO       = syscall.Errno(0x79)
	ERESTART        = syscall.Errno(0x55)

		p.ipv6Enabled = true
		p.ipv4MappedIPv6Enabled = true
		return
	}

	s, err := sysSocket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
	switch err {
	case syscall.EAFNOSUPPORT, syscall.EPROTONOSUPPORT:
	case nil:
		poll.CloseFunc(s)
		p.ipv4Enabled = true
	}
	var probes = []struct {
		laddr TCPAddr
		value int
	}{
		// IPv6 communication capability
		{laddr: TCPAddr{IP: ParseIP("::1")}, value: 1},

	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x41)
	EPIPE           = syscall.Errno(0x20)
	EPROCLIM        = syscall.Errno(0x53)
	EPROTO          = syscall.Errno(0x79)
	EPROTONOSUPPORT = syscall.Errno(0x3e)
	EPROTOTYPE      = syscall.Errno(0x3c)
	ERANGE          = syscall.Errno(0x22)
	EREMOTE         = syscall.Errno(0x5d)
	ERESTART        = syscall.Errno(0x52)

	EOWNERDEAD      = syscall.Errno(0x3a)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x7b)
	EPIPE           = syscall.Errno(0x20)
	EPROTO          = syscall.Errno(0x47)
	EPROTONOSUPPORT = syscall.Errno(0x78)
	EPROTOTYPE      = syscall.Errno(0x62)
	ERANGE          = syscall.Errno(0x22)
	EREMCHG         = syscall.Errno(0x52)
	EREMOTE         = syscall.Errno(0x42)

	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x41)
	EPIPE           = syscall.Errno(0x20)
	EPROCLIM        = syscall.Errno(0x53)
	EPROTO          = syscall.Errno(0x79)
	EPROTONOSUPPORT = syscall.Errno(0x3e)
	EPROTOTYPE      = syscall.Errno(0x3c)
	ERANGE          = syscall.Errno(0x22)
	EREMOTE         = syscall.Errno(0x5d)
	ERESTART        = syscall.Errno(0x52)

	EPROCLIM        = syscall.Errno(0x43)
	EPROCUNAVAIL    = syscall.Errno(0x4c)
	EPROGMISMATCH   = syscall.Errno(0x4b)
	EPROGUNAVAIL    = syscall.Errno(0x4a)
	EPROTO          = syscall.Errno(0x5c)
	EPROTONOSUPPORT = syscall.Errno(0x2b)
	EPROTOTYPE      = syscall.Errno(0x29)
	ERANGE          = syscall.Errno(0x22)
	EREMOTE         = syscall.Errno(0x47)
	EROFS           = syscall.Errno(0x1e)

	EPROCLIM        = syscall.Errno(0x43)
	EPROCUNAVAIL    = syscall.Errno(0x4c)
	EPROGMISMATCH   = syscall.Errno(0x4b)
	EPROGUNAVAIL    = syscall.Errno(0x4a)
	EPROTO          = syscall.Errno(0x64)
	EPROTONOSUPPORT = syscall.Errno(0x2b)
	EPROTOTYPE      = syscall.Errno(0x29)
	EPWROFF         = syscall.Errno(0x52)
	EQFULL          = syscall.Errno(0x6a)
	ERANGE          = syscall.Errno(0x22)

	EPROCLIM        = syscall.Errno(0x43)
	EPROCUNAVAIL    = syscall.Errno(0x4c)
	EPROGMISMATCH   = syscall.Errno(0x4b)
	EPROGUNAVAIL    = syscall.Errno(0x4a)
	EPROTO          = syscall.Errno(0x5f)
	EPROTONOSUPPORT = syscall.Errno(0x2b)
	EPROTOTYPE      = syscall.Errno(0x29)
	ERANGE          = syscall.Errno(0x22)
	EREMOTE         = syscall.Errno(0x47)
	EROFS           = syscall.Errno(0x1e)