I have a node running on my computer and whilst my VPN is on it only has outbound connections, but i was using bitsquare today and noticed that i had an incoming connection on my core node whilst using the vpn. so i checked it out and it was from my local ip and was a Bitcoinj connection by bitsquare, what is the purpose for this? does anyone know?
BitcoinJ is a SPV implementation, it gets data from full nodes. Your "no external connection" rule is probably a firewall rule. If you did not set the node to listen=0 it will still accept inbound connections if its reachable.
