Every once in a while, this web app will send getnodes requests to every node on the list. If a node responds with a valid sendnodes packet, its status will be set to ONLINE.
We also try to see if a node also functions as a TCP relay. This is done by sending a handshake request packet. If a relay responds with a valid handshake response packet, a list of TCP ports will be shown as extra information. If a node only functions as a TCP relay, its status will be set to ONLINE.
If a node doesn't respond to either of those requests, its status will be set to OFFLINE.