On Wednesday 22 September 2004 11:33, fenfire@xxxxxxxxxxx wrote: > > When V receiving that packet, it sends ICMP echo-reply packet to D, AND > > FORWARDS TO D ALL DATA IN PAYLOAD! > > This could also be used by peer-to-peer networks to achieve sender > anonymity. (Of course you could also directly send UDP packets with forged > source addresses...) A few people started work on this. We built a crude program that would transfer files over UDP with spoofed addresses. http://udpp2p.sourceforge.net/ (We haven't worked on it in ages.) Main problems? ISPs filter outbound on their routers, which can cause problems, and the other big problem was the handshaking/acking/resending. How can you tell the guy that you missed a packet if you have no way of contacting him. We used a broadcast method to perform the searches, and "ttl"s to stop it going on for ever but we weren't sure how it would scale. Also the ICMP is a great way of transferring data - just bounce a stream of ICMP echo-requests off any host that returns them and has a lot of bandwidth - google, bbc.co.uk, cisco, etc, and if you set the source address as the target address, no-one knows who you are. -- Random russian saying: The horse may run quickly, but it can't escape its own tail. pgp: http://gk.umtstrial.co.uk/~calum/keys.php Linux 2.6.7-hardened-r7 14:42:33 up 9 days, 2:46, 1 user, load average: 2.33, 2.11, 1.94
