Raw Sockets on Linux

First you disable your network card’s automatic checksumming:

sudo ethtool -K eth1 tx off

Then send your packet, using a SOCK_RAW socket:

#!/usr/bin/env python
from socket import socket, AF_PACKET, SOCK_RAW
s = socket(AF_PACKET, SOCK_RAW)
s.bind(("eth1", 0))

# We're putting together an ethernet frame here, 
# but you could have anything you want instead
# Have a look at the 'struct' module for more 
# flexible packing/unpacking of binary data
# and 'binascii' for 32 bit CRC
src_addr = "\x01\x02\x03\x04\x05\x06"
dst_addr = "\x01\x02\x03\x04\x05\x06"
payload = ("["*30)+"PAYLOAD"+("]"*30)
checksum = "\x1a\x2b\x3c\x4d"
ethertype = "\x08\x01"

s.send(dst_addr+src_addr+ethertype+payload+checksum)

Found a mistake? Have a question or improvement idea? Let me know.

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