forwarding with ttl=1

[Alexander Botov]

> TTL (Time To Live) is a counter value in an IP packet that gets decremented
> by every "hop" (router). When it reaches a value of zero, the packet is
> discarded.

One more thing . If the packet is going to be forwarded and the TTL has value of 1 than the hop discards the packet .

"A system should never receive IP datagram with TTL of 0 , but Net/3 generates the correct ICMP error if this happens since ip_ttl is examined after the packet is considered for local delivery and before it is forwarded"
[TCP/IP Illustrated , Volume 2 - Gary R. Wright , W.Richard Stevens]