Networking - What is the TTL (Time to Live)? Why is it
required? - July 31, 2009 at 17:00 pm by Vidya Sagar
What is the TTL (Time to Live)? Why is it required?
TTL is a value in data packet of Internet Protocol. It communicates to the
network router whether or not the packet should be in the network for too long
or discarded. Usually, data packets might not be transmitted to their intended
destination within a stipulated period of time. The TTL value is set by a
system default value which is an 8-bit binary digit field in the header of the
packet. The purpose of TTL is, it would specify certain time limit in seconds,
for transmitting the packet header. When the time is exhausted, the packet
would be discarded. Each router receives the subtracts count, when the packet
is discarded, and when it becomes zero, the router detects the discarded
packets and sends a message, Internet Control Message Protocol message back to
the originating host.