Honeyd Implementation

Central dispatcher gets all packets.
Callbacks for TCP, UDP and ICMP.
Other protocols cause packet to be dropped silently.

All output packets pass personality engine.
Adjusts packets according to configured personality.

ICMP handler very simple.
Replies to ICMP Echo Requests only.

UDP handler knows closed and open states.
Closed UDP port generates ICMP Port Unreachable message.
Traceroute works.