Using traceroute provides round trip time for each hop along the path and indicates if a hop fails to respond. The round trip time is the time a packet takes to reach the remote host and for the response from the host to return. An asterisk (*) is used to indicate a lost or unreplied packet. This information can be used to locate a problematic router in the path. If the display high response times or data losses from a particular hop, this is an indication that the resources of the router or its connections may be stressed. IPv4 TTL and IPv6 Hop Limit Traceroute makes use of a function of the TTL field in IPv4 and the Hop Limit field in IPv6 in the Layer 3 headers, along with the ICMP time exceeded message. Play the animation in the figure to see how Traceroute takes advantage of TTL. The sequence of messages sent from traceroute will have a TTL field value of 1. This causes the TTL to time out the IPv4 packet at the first router. This router then responds with an ICMPv4 message. Traceroute now has the address of the first hop. Traceroute then progressively increments the TTL field (2, 3, 4...) for each sequence of messages. This provides the trace with the address of each hop as the packets timeout further down the path. The TTL field continues to be increased until the destination is reached, or it is incremented to a predefined maximum. After the final destination is reached, the host responds with either an ICMP port unreachable message or an ICMP echo reply message instead of the ICMP time exceeded message. Please log into before accessing this course. 7.3.2.5Packet Tracer Verifying IPv4 and IPv6 Addressing – Packet Tracer Verifying IPv4 and IPv6 Addressing – IPv4 and IPv6 can coexist on the same network. From the command prompt of a PC, there are some differences in the way commands are issued and in the way output is displayed. Please log into before accessing this course. Packet Tracer Pinging and Tracing to Test the Path –
Using traceroute provides round trip time for each hop along the path and indicates if a hop fails to respond. The round trip time is the time a packet takes to reach the remote host and for the response from the host to return. An asterisk (*) is used to indicate a lost or unreplied packet. This information can be used to locate a problematic router in the path. If the display high response times or data losses from a particular hop, this is an indication that the resources of the router or its connections may be stressed. IPv4 TTL and IPv6 Hop Limit Traceroute makes use of a function of the TTL field in IPv4 and the Hop Limit field in IPv6 in the Layer 3 headers, along with the ICMP time exceeded message. Play the animation in the figure to see how Traceroute takes advantage of TTL. The sequence of messages sent from traceroute will have a TTL field value of 1. This causes the TTL to time out the IPv4 packet at the first router. This router then responds with an ICMPv4 message. Traceroute now has the address of the first hop. Traceroute then progressively increments the TTL field (2, 3, 4...) for each sequence of messages. This provides the trace with the address of each hop as the packets timeout further down the path. The TTL field continues to be increased until the destination is reached, or it is incremented to a predefined maximum. After the final destination is reached, the host responds with either an ICMP port unreachable message or an ICMP echo reply message instead of the ICMP time exceeded message. Please log into before accessing this course. 7.3.2.5Packet Tracer – Verifying IPv4 and IPv6 Addressing Packet Tracer – Verifying IPv4 and IPv6 Addressing IPv4 and IPv6 can coexist on the same network. From the command prompt of a PC, there are some differences in the way commands are issued and in the way output is displayed. Please log into before accessing this course. Packet Tracer – Pinging and Tracing to Test the Path
R&S%20Chapter%207.docx