#!/bin/env python3
import sys
from scapy.all import *

ip = IP()
ip.dst = '8.8.8.8'
icmp = ICMP()

for TTL in range(1, 20):
  ip.ttl = TTL
  reply = sr1(ip/icmp, timeout=2, verbose=0)
  if reply is None:
      print("Router: *** (hops = {})".format(TTL))
  else:
      print("Router: {} (hops = {})".format(reply.src, TTL))