title: Which peers does DHT and PEX keep track of
body: <p>I have a question regarding DHT and PEX.  I have read a few articles that suggest that DHT updates other peers as to who is actively in a swarm a for a torrent.  </p>
  
  <p>1) When I have a torrent that's currently in a swarm, I check the DHT and PEX activity and shows that they are both active.  I also see, for example, something like this:  124 seeds (124 seeds currently in swarm) 459 peers (235 in swarm).</p>
  
  <p>I always thought that DHT updates peers about other peers in a swarm.  Thus, Where are the other 224 peers (ie 459-235= 224) coming from? Are these peers that have paused or stopped their download? Are they simply peers that were part of the swarm recently and will eventually be taken off the DHT after a few updates?</p>
  
  <p>2) Does DHT maintain torrent info hashes of users (peers), that have removed the torrent from active uploading/downloading (ie removed it from the swarm)? For example, I have clicked on a magnet link and the metadata is downloaded and my file begins to download.  After a while, I use the "remove" button on utorrent and remove the torrent which had been in the swarm and I also erase the partially downloaded file from my downloads.  But, I don't erase the data/torrent files from my Users/~/Library/Application Support/uTorrent.  Do DHT and PEX still consider you an active peer for the file? For example, when DHT refreshes/updates its table, would DHT add your ip adress/peer as still being a source for the file, even if you are not actively in the swarm?  How about PEX? would it still consider your node one that still possesses the file?</p>
  
  <p>Any information on this would be helpful.</p>
  
  <p>Thanks in advance</p>