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Tracert – H3C Technologies H3C WX5500E Series Access Controllers User Manual

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3

1.1.2.2

1.1.1.2

1.1.1.1

--- 1.1.2.2 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 1/11/53 ms

The test procedure with the ping –r command (see

Figure 1

) is as follows:

1.

The source device (Device A) sends an ICMP echo request with the RR option being empty to the
destination device (Device C).

2.

The intermediate device (Device B) adds the IP address of its outbound interface (1.1.2.1) to the RR
option of the ICMP echo request, and forwards the packet.

3.

Upon receiving the request, the destination device copies the RR option in the request and adds the
IP address of its outbound interface (1.1.2.2) to the RR option. Then the destination device sends

an ICMP echo reply.

4.

The intermediate device adds the IP address of its outbound interface (1.1.1.2) to the RR option in
the ICMP echo reply, and then forwards the reply.

5.

Upon receiving the reply, the source device adds the IP address of its inbound interface (1.1.1.1)

to the RR option. Finally, you can get detailed information about routes from Device A to Device C:
1.1.1.1 <-> {1.1.1.2; 1.1.2.1} <-> 1.1.2.2.

Tracert

Tracert (also called "Traceroute") enables you to get the IP addresses of Layer 3 devices in the path to a

specific destination. You can use tracert to test network connectivity and identify the failed nodes.

Figure 2 Traceroute operation

Tracert uses received ICMP error messages to get the IP addresses of devices. As shown in

Figure 2

,

tracert works as follows:

1.

The source device (Device A) sends a UDP packet with a TTL value of 1 to the destination device
(Device D). The destination UDP port is not used by any application on the destination device.