when using (traceroute -q 1 serverAddress), we know that it starts with TTL(Time to Live) = 1. when it goes through router, the router decrements TTL by 1. If TTL becomes 0 at that router, it sends back ICMP error TTL exceeded message. Now, tell me here router will send the error message back to the client(means me/us). Now how will router know what TTL to set. When i used wireshark, i got the receiving ICMP error message showing TTL=64 for udp packet with initial TTL=5. How does the router set the TTL??