Chris Wagner wrote: > So it's really a max hops limit. How did it get a name like TTL?? What > function does it serve? Besides providing a mechanism to expire lost > packets... What role does each host's TTL setting play in a ping or trace?
When you receive a ping reponse the TTL is determined by the remote computer's TTL setting. If that computer's default TTL is 64 and you are 20 hops away you will see a TTL of 44 on the ping responses. Win95/NT3.51 both had a default TTL of 32 which is definitely not sufficient for today's Internet. Those computers will find a lot of their packets not reaching destinations. There's quite a lot of documentation about this on the Internet, here are a couple of URLs: http://www.switch.ch/docs/ttl_info.html http://cne.gsfc.nasa.gov/tcpipsvcs/netwkutil/traceroutetutorial.html Linux 2.0.x appears to have a default TTL setting of 64. Linux 2.2.x appears to have a default TTL setting of 255. Win98/NT4 have a default TTL setting of 128 IIRC. I don't remember Win2k's setting right now. I would assume the Linux default TTL is tunable via /proc but perhaps not, Windows is tunable via the registry. Fraser
