H3C Technologies H3C SecPath F1000-E - Manual (Page 18)

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2. The first hop (Device B, the first Layer 3 device that receives the packet) responds by sending a
TTL-expired ICMP error message to the source, with its IP address 1.1.1.2 encapsulated. In this
way, the source device can get the address of the first Layer 3 device (1.1.1.2).
3. The source device sends a packet with a TTL value of 2 to the destination device.
4. The second hop (Device C) responds with a TTL-expired ICMP error message, which gives the
source device the address of the second Layer 3 device (1.1.2.2).
5. The process continues until the packet sent by the source device reaches the ultimate destination
device. Because no application uses the destination port specified in the packet. The destination
device responds with a port-unreachable ICMP message to the source device, its IP address
encapsulated. This way, the source device gets the IP address of the destination device (1.1.3.2).
6. The source device thinks that the packet has reached the destination device after receiving the
port-unreachable ICMP message, and the path to the destination device is 1.1.1.2 to 1.1.2.2 to
1.1.3.2.
Executing the tracert operation in the Web interface
The Web interface does not support IPv6 tracert operations.
Prerequisites
Before performing the tracert operation in the Web interface:
• Execute the ip ttl-expires enable command on the intermediate devices to enable the sending of
ICMP timeout packets
• Execute the ip unreachables enable command on the destination device to enable the sending of
ICMP destination unreachable packets.
Executing the tracert command
1. Select Network > Diagnostic Tools from the navigation tree and click the Trace Route tab.
The page for executing the tracert operation appears,