ImperialViolet

Scapy[via LtU] is a domain specific language for manipulating network packets. Actually, it's a thin wrapper around a Python read-eval loop and all the better for it.

Also, it makes for a very neat Python packet manipulation library. Have a look at the homepage (linked to above) for a transcript demonstrating some of its neat little features.

% python scapy.py
Welcome to Scapy (0.9.11.1beta)
>>> net = Net ("127.0.0.0"/24)
>>> list = IP (src = Net)
>>> for x in list:
...  print repr (x)
...
<snip>
<IP src=127.0.0.246 |>
<IP src=127.0.0.247 |>
<IP src=127.0.0.248 |>
<IP src=127.0.0.249 |>
<snip>
>>> Ether()/IP()/TCP()/"123"