docs: def dyndns_add(nameserver, name, rdata, type="A", ttl=10):
      """Send a DNS add message to a nameserver for "name" to have a new "rdata"
  dyndns_add(nameserver, name, rdata, type="A", ttl=10) -> result code (0=ok)
  
  example: dyndns_add("ns1.toto.com", "dyn.toto.com", "127.0.0.1")
  RFC2136
  """
      zone = name[name.find(".") + 1:]
      r = sr1(IP(dst=nameserver) / UDP() / DNS(opcode=5,
                                               qd=[DNSQR(qname=zone, qtype="SOA")],  # noqa: E501
                                               ns=[DNSRR(rrname=name, type="A",
                                                         ttl=ttl, rdata=rdata)]),
              verbose=0, timeout=5)
      if r and r.haslayer(DNS):
          return r.getlayer(DNS).rcode
      else:
          return -1