title: Scapy Sniff 'iface' attribute data type
body: <p>Using scapy 2.4.3 (installed on pip using <code>"pip install --pre scapy[complete]"</code>) with Python 3.7.2</p>
  
  <p>Using the sniff function in scapy, what should the data type that goes into the <code>iface</code> parameter be? I used the <code>scapy.all.show_interfaces()</code> function to list the known interfaces, and this is the output:</p>
  
  <pre><code>INDEX  IFACE                                           IP               MAC
  13     Realtek PCIe GBE Family Controller              169.254.142.162  HewlettP:47:07:dc
  10     Microsoft Wi-Fi Direct Virtual Adapter          169.254.246.19   Azurewav:80:86:ff
  7      Realtek RTL8723DE 802.11b/g/n PCIe Adapter      192.168.0.7      Azurewav:80:86:ff
  -1     [Unknown] Adapter for loopback traffic capture  None             ff:ff:ff:ff:ff:ff
  </code></pre>
  
  <p>When I put <code>"Realtek PCIe GBE Family Controller"</code> into the sniff function, there is no <code>"scapy.error.Scapy_Exception: Interface is invalid (no pcap match found) !"</code> error, so I know that the interface is valid. However, I am receiving this error: <code>AttributeError: 'str' object has no attribute 'is_invalid'</code>. If I change the <code>iface</code> attribute to <code>scapy.all.ifaces.dev_from_index(-1)</code>, then the error is <code>OSError: exception: access violation reading 0x00000000000002A8</code>. What does the iface data type have to be for it to be parsed correctly and work???</p>