Posts tagged “firewall”

How the passive mode in P2P programs like KaZaA and Gnutella worksMar 16, 2003

A clever network friend explained passive mode in P2P apps to me. It's all about NAT and firewalls: if both parties are behind NAT with no port mapping, neither can initiate a direct connection, making efficient file transfer impossible. The peer network can relay queries but not bulk data.