Here is the console log from my last session. Note that I was in a server before I decided to try again, and interceptor was the guy trying to join.
Got connect request from IP:68.197.185.107:28100
net name = intercepter66
AUTHCHECK: intercepter66 = internet client -> internet server, regular auth
Authentication Failed for intercepter66 (68.197.185.107).
Issuing Disconnect packet.
CDROP: 258884 IP:68.197.185.107:28100
Posting to master server
Posting to rtb server
Got connect request from IP:68.197.185.107:28100
net name = intercepter66
AUTHCHECK: intercepter66 = internet client -> internet server, regular auth
Authentication Failed for intercepter66 (68.197.185.107).
Issuing Disconnect packet.
CDROP: 258888 IP:68.197.185.107:28100
Got connect request from IP:68.197.185.107:28100
net name = intercepter66
AUTHCHECK: intercepter66 = internet client -> internet server, regular auth
Authentication Failed for intercepter66 (68.197.185.107).
Issuing Disconnect packet.
CDROP: 258890 IP:68.197.185.107:28100
Got connect request from IP:68.197.185.107:28100
net name = intercepter66
AUTHCHECK: intercepter66 = internet client -> internet server, regular auth
Authentication Failed for intercepter66 (68.197.185.107).
Issuing Disconnect packet.
CDROP: 258905 IP:68.197.185.107:28100
Slayer (Server): Deactivating Slayer
Issuing Disconnect packet.
Exporting server prefs
Exporting client prefs
Exporting client config
Exporting rtb prefs
Slayer (Client): Deactivating Slayer
That is my external IP.