title: python/scapy - packets sent but unable to receive them
body: <p>I'm trying to do an ARP scan and print MAC addresses of reachable IP addresses.</p>
  <p>Here's the part of my code where I use ARP ping method :</p>
  <pre><code>ans, unans = srp(Ether(dst=&quot;ff:ff:ff:ff:ff:ff&quot;)/ARP(pdst=&quot;192.168.1.0/24&quot;),timeout=2)
  ans.summary(lambda s,r: r.sprintf(&quot;%Ether.src% %ARP.psrc%&quot;))
  </code></pre>
  <p>I put a random IP address for the example.</p>
  <p>Here's my response, I really don't understand why my packets are not received :</p>
  <pre><code>Begin emission:
  Finished sending 1 packets.
  Received 0 packets, got 0 answers, remaining 1 packets
  </code></pre>