These are simple scripts that emulate a fluke-y network behind a
TUN/TAP interface. The point is to provide Scapy exercises for
learning basic protocols: ARP, TCP/IP, ICMP, DHCP, DNS, etc.

This should work on both Linux (where primarily developed) and MacOS
(your mileage may vary). 

pytap.py -- simple functions to create/open a TAP pseudo-device
pong.py  -- emulate ARP and ICMP responses from any host
tcp.py   -- the above + 'rot13' service on any TCP port

When something fails, look at the code -- there might be a rant there
on what we found to not work and why :)