DHT
BitTorrent DHT Protocol && DHT Spider.
...The default crawl mode configuration costs about 300M RAM. Set MaxNodes and BlackListMaxSize to fit yourself. DHT aims to implement the standard BitTorrent DHT protocol, not born for crawling the DHT network. NAT Traversal issue. You run the crawler in a local network. It will block ip which looks bad and a good ip may be misjudged.