Windows operating systems have traditionally transmitted network traffic with a starting TTL value of 128, whereas Linux/Unix operating systems have traditionally transmitted network traffic with a starting TTL value of 64. By assuming that no more than 64 hops should be made to get from one device to another, it can be safely assumed that Windows systems will transmit replies with a range of TTL values between 65 and 128 and that Linux/Unix systems will transmit replies with a range of TTL values between 1 and 64. This identification method can become less useful when devices exist between the scanning system and the remote destination that intercept requests and then repacks them.