H3C Technologies H3C MSR 5600 - Manual (Page 17)

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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.
Prerequisites
Before you use a tracert command, perform the tasks in this section.
For an IPv4 network:
• Enable sending of ICMP timeout packets on the intermediate devices (devices between the source
and destination devices). If the intermediate devices are H3C devices, execute the ip ttl-expires
enable command on the devices. For more information about this command, see Layer 3—IP
Services Command Reference.
• Enable sending of ICMP destination unreachable packets on the destination device. If the
destination device is an H3C device, execute the ip unreachables enable command. For more
information about this command, see Layer 3—IP Services Command Reference.
For an IPv6 network:
• Enable sending of ICMPv6 timeout packets on the intermediate devices (devices between the
source and destination devices). If the intermediate devices are H3C devices, execute the ipv6
hoplimit-expires enable command on the devices. For more information about this command, see
Layer 3—IP Services Command Reference.
• Enable sending of ICMPv6 destination unreachable packets on the destination device. If the
destination device is an H3C device, execute the ipv6 unreachables enable command. For more
information about this command, see Layer 3—IP Services Command Reference.
Using a tracert command to identify failed or all nodes in a
path
Execute tracert commands in any view.
Task Command
Display the routes from source to
destination.
• For IPv4 networks:
tracert [ -a source-ip | -f first-ttl | -m max-ttl | -p port | -q packet-number
| -t tos | -vpn-instance vpn-instance-name | -w timeout ] * host
• For IPv6 networks:
tracert ipv6 [ -f first-hop| -m max-hops | -p port | -q packet-number | -t
traffic-class | -vpn-instance vpn-instance-name | -w timeout ] * host
For more information about the tracert mpls ipv4 command, see MPLS Command Reference.
Tracert example
Network requirements
As shown in Figure 3 , Device A failed to Telnet Device C.