title: What are all the Flag Values from ARP Cache entries?
body: <p>When running "arp -a" on a linux machine, one of the values for each entry returned is "Flags." I've seen 0x0, 0x2, and 0x6 as possible values. All I have gathered so far is that 0x6 represents a permanent (ie: static and not dynamic) entry.</p>
  
  <p>Is there a list somewhere of all of the possible flags for an arp cache entry? Can there ever be more than one flag for an entry?</p>