Tracert example
Network requirements
As shown in Figure 3, Device A failed to Telnet to Device C.
Test the network connectivity between Device A and Device C. If they cannot reach each other, locate the failed nodes in the network.
Figure 3: Network diagram
Configuration procedure
Configure the IP addresses for devices as shown in Figure 3.
Configure a static route on Device A.
<DeviceA> system-view [DeviceA] ip route-static 0.0.0.0 0.0.0.0 1.1.1.2 [DeviceA] quit
Use the ping command to test connectivity between Device A and Device C.
<DeviceA> ping 1.1.2.2 Ping 1.1.2.2(1.1.2.2): 56 -data bytes, press CTRL_C to break Request time out Request time out Request time out Request time out Request time out --- Ping statistics for 1.1.2.2 --- 5 packet(s) transmitted,0 packet(s) received,100.0% packet loss
The output shows that Device A and Device C cannot reach each other.
Use the tracert command to identify failed nodes:
# Enable sending of ICMP timeout packets on Device B.
<DeviceB> system-view [DeviceB] ip ttl-expires enable
# Enable sending of ICMP destination unreachable packets on Device C.
<DeviceC> system-view [DeviceC] ip unreachables enable
# Execute the tracert command on Device A.
<DeviceA> tracert 1.1.2.2 traceroute to 1.1.2.2 (1.1.2.2) 30 hops at most,40 bytes each packet, press CTRL_C to break 1 1.1.1.2 (1.1.1.2) 1 ms 2 ms 1 ms 2 * * * 3 * * * 4 * * * 5 <DeviceA>
The output shows that Device A can reach Device B but cannot reach Device C. An error has occurred on the connection between Device B and Device C.
To identify the cause of the problem, execute the following commands on Device A and Device C:
Execute the debugging ip icmp command and verify that Device A and Device C can send and receive the correct ICMP packets.
Execute the display ip routing-table command to verify that Device A and Device C have a route to each other.