H3C S7500 Series Command Manual page 19

Command Manual – System Maintenance and Debugging
H3C S7500 Series Ethernet Switches
-q num-packet: Sets the number of packets to be sent every time. The num-packet
argument ranges from 0 to 65,535 and defaults to 3.
-w timeout: Sets the timeout time to wait for ICMP error packets. The timeout argument
ranges from 0 to 65,535 and defaults to 5,000 (in milliseconds).
host: IP address of the destination host or the host name of the remote system, 1 to 30
characters long.
clns: Connectionless network service, a suit of protocols in OSI system, including CLNP,
ISIS and ESIS.
-m max-TTL: Sets a maximum TTL value. The max-TTL argument ranges from 1 to 255
and defaults to 30.
-n num-packet: Indicates the integral number of the sent test packets. The num-packet
argument ranges from 0 to 65535 and defaults to 3.
-t timeout: Sets the timeout time of the tracert command. The timeout argument, in
seconds, ranges from 0 to 65535 and defaults to 5.
-v: Explains the error if the response packet error occurs. If no error occurs, after you
execute the command, the result is the same as the command is executed without -v.
nsap-address: NSAP address of the destination host.
Description
Use the tracert command to trace the gateways the test packets passes through during
its journey from the source to the destination. This command is mainly used to check
the network connectivity. It can help you locate the trouble spot of the network.
The executing procedure of the tracert command is as follows: First, the source sends
a packet with the TTL of 1, and the first hop device returns an ICMP error message
indicating that it cannot forward this packet because of TTL timeout. Then, the source
resends a packet with the TTL of 2, and the second hop device also returns an ICMP
TTL timeout message. This procedure goes on and on until a packet gets to the
destination or the maximum TTL is reached. During the procedure, the system records
the source address of each ICMP TTL timeout message in order to offer the path that
the packets pass through to the destination.
If you find that the network is in trouble by using the ping command, you can use the
tracert command to find where the trouble is in the network.
The tracert command can output the IP addresses of all the gateways the packets pass
through to the destination. It output the string "***" if a gateway times out.
Examples
# Trace the gateways the packets pass through during its journey to the destination with
IP address 18.26.0.115.
<H3C> tracert 18.26.0.115
Chapter 2 Network Connectivity Test
2-4
Commands