Using The Traceroute Command - Cisco ASR 9000 Getting Started Manual

Basic Troubleshooting Commands
Examples
The following example shows a successful ping attempt:
RP/0/RSP0/CPU0:router# ping 10.233.233.233
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.233.233.233, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/7 ms
In the next example, an unsuccessful ping attempt is shown:
RP/0/RSP0/CPU0:router# ping 10.1.1.1
Mon May 31 23:53:30.820 DST
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms

Using the traceroute Command

Use the traceroute command in EXEC mode to discover the routes that packets take when traveling to
their destination. Enter a hostname or an IP address as an argument to this command.
This command works by taking advantage of the error messages generated by routers when a datagram
exceeds its time-to-live (TTL) value.
The traceroute command starts by sending probe datagrams with a TTL value of 1, causing the first
router to discard the probe datagram and send back an error message. The traceroute command sends
several probes at each TTL level and displays the round-trip time for each.
The traceroute command sends one probe at a time. Each outgoing packet may result in one or two error
messages. A time exceeded error message indicates that an intermediate router has seen and discarded
the probe. A destination unreachable error message indicates that the destination node has received the
probe and discarded it because it could not deliver the packet. If the timer times out before a response
comes in, the traceroute command prints an asterisk (*).
The traceroute command terminates when the destination responds, the maximum TTL is exceeded, or
the user interrupts the trace with the escape sequence.
Cisco ASR 9000 Series Aggregation Services Router Getting Started Guide
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Troubleshooting the Cisco IOS XR Software
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