TTL value in PING response

[avilt]

Can someone explain to me in details on what basis the TTL value is displayed when we ping a remote host.

I am pinging a remote host from my WindowsXP system. Sometimes the TTL value is less than 127 and some times its close to 255. Both the resources are on internet.

[Vishnu Vardhan S]

Hi Richard,

Tried to google your info but no luck. 

Would you be kind enough to explain this in detail please. I would appreciate if you could share any documents? 

Not sure how my router which is default gateway setting the TTL value for a ping which my PC generated. 

[KRISTOF SLACHMUYLDERS]

Hello,

Found this clarifying paragraph in the original internet protocol RFC791 document.

The Time to Live is an indication of an upper bound on the lifetime of
  an internet datagram.  It is set by the sender of the datagram and
  reduced at the points along the route where it is processed.  If the
  time to live reaches zero before the internet datagram reaches its
  destination, the internet datagram is destroyed.  The time to live can
  be thought of as a self destruct time limit.

Basically, it prevents a packet from looping around the network forever.

Cheers!

Kristof

[richard459512]

Hago esta explicación para los de habla en español y si llegaste hasta aqui buscando respuesta.

Cuando un paquete ping llega a su destino, el destino revisa el valor del TTL y si está todo bien, entonces responde REINICIANDO  en valor del TTL: Si responde windows, lo reinicia con 128; si responde cisco, lo reinicia con 255. Luego en su camino de retorno vuelve a decrementarse y ese valor decrementado es el que se presenta al que hizo el ping.