The Hop Limit field is a 1-bytedata field in the header of the IPv6 protocol
. This is the datagram lifetime limitation function, which is referred to as Time To Live (TTL) in other IP headers. The renaming of the name is accompanied by a clearer assignment of terms, since the number of hops entered indicates how many routers the datagram
can be routed through. Each time a router is passed through, the number entered in the Hop Limit field is reduced by one. If the Hop Limit field has the value zero, it is discarded.