H3C S9500 Series Operation Manual page 1430

Operation Manual – System Maintenance and Debugging
H3C S9500 Series Routing Switches
1.4.7 Testing Gateways Passed by Packets from the Source Host to the
Destination One
Test the gateways passed by the packets from the source host to the destination one to
check whether the network is connected and analyze where the fault occurs in the
network.
Test the gateways
passed by the packets
from the source host to
the destination one to
check whether the
network is connected
The execution process of the tracert command is described as follows: Send a packet
with TTL value as 1 and the first hop sends back an ICMP error message indicating that
the packet cannot be sent, for the TTL is timeout. Re-send the packet with TTL value as
2 and the second hop returns the TTL timeout message. The process is carried out
over and over until the packet reaches the destination. The purpose to carry out the
process is to record the source address of each ICMP TTL timeout message, so as to
provide the route of an IP packet to the destination.
Caution:
At present, the device does not support using the tracert command to check whether a
network is reachable and identify failed node(s) in the event of network failure in an
MPLS domain.
1.5 Command Line Parser Cache Function
When the device is running, it takes long time to execute and resolve some commands.
In particular, batch execution of this type of commands may increase the system load,
or even affect the normal operation of the system. Therefore, the switch provides the
command line parser cache function to improve the resolution and execution efficiency
of commands.
To do...
tracert [ -a source-IP | -f
first-TTL | -m max-TTL | -p
port | -q num-packet |
-vpn-instance
vpn-instance-name | -w
timeout ] string
Chapter 1 System Maintenance and
Use the command...
1-8
Debugging
Remarks
You can use this
command in any view.