TTL with 0

[lohit prasad]

Hi 

PC A >>>>> R >>>>>>>R2 > R3> >>R4>>> google.com

If I ping from my laptop PC A  to google.com with TTL value 0 then My packet is going out of interface and R is replying ICMP TTL time exceeded.

How come PC A forwarded packet?  

If I send ping -m 0 to IP address of R then it reply back. How come ?

R is my home internet bo ( may be L3 switch or Router no idea what it is)  when I do traceroute I see R, R2,R3,R4

[Paul Chapman]

Hi -

Do you have a packet trace showing that the TTL is actually 0?  Logically the PC shouldn't send, but if your ping application is successfully setting the TTL to 0, then the first hop router (R) is obligated to send you an ICMP TTL Exceeded (type 11) message.

PSC

[lohit prasad]

Yes I have.