big_sender.py

#!/usr/bin/env python

# Send a big UDP packet to server
import IN
import socket
import sys

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

MAX = 65535
PORT = 1060

if len(sys.argv) != 2:
    print >>sys.stderr, 'usage: big_sender.py host'
    sys.exit(2)

hostname = sys.argv[1]

s.connect((hostname, PORT))
s.setsockopt(socket.IPPROTO_IP, IN.IP_MTU_DISCOVER,
             IN.IP_PMTUDISC_DO)
try:
    s.send('#' * 65000)
except socket.error:
    print 'The message did not make it'
    option = getattr(IN, 'IP_MTU', 14)
    print 'MTU:', s.getsockopt(socket.IPPROTO_IP, option)
else:
    print 'The big msg was sent! Your network supports really big packets!'