I've been running LimeWire on a NAT'ed port, and it never figures out on its own that it is not firewalled.

BearShare has automatically detected whether it is firewalled for a long time. When BS gets an incoming connection from a public remote IP address, BS decides it is not firewalled, and starts returning non-FW Query Hits.

But with LimeWire, even if I even connect directly into the server with a Gnutella host connection from an external public IP address, and even if I connect directly to download (using a manually crafted HTTP request) LW still sends out firewalled Query Hits.

It seems that unless I check the "Force IP" checkbox in Setup, LW only sends out firewalled Query Hits.