CLI Reference Guide-R04

Chapter 31 | IP Interface Commands
IPv4 Interface
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input errors
5867 output
Console#
traceroute This command shows the route packets take to the specified destination.
Syntax
traceroute host
host - IP address or alias of the host.
Default Setting
None
Command Mode
Privileged Exec
Command Usage
◆ Use the traceroute command to determine the path taken to reach a specified
destination.
◆ A trace terminates when the destination responds, when the maximum
timeout (TTL) is exceeded, or the maximum number of hops is exceeded.
◆ The traceroute command first sends probe datagrams with the TTL value set at
one. This causes the first router to discard the datagram and return an error
message. The trace function then sends several probe messages at each
subsequent TTL level and displays the round-trip time for each message. Not all
devices respond correctly to probes by returning an “ICMP port unreachable”
message. If the timer goes off before a response is returned, the trace function
prints a series of asterisks and the “Request Timed Out” message. A long
sequence of these messages, terminating only when the maximum timeout
has been reached, may indicate this problem with the target device.
◆ If the target device does not respond or other errors are detected, the switch
will indicate this by one of the following messages:
■
* - No Response
■
H - Host Unreachable
■
N - Network Unreachable
■
P - Protocol Unreachable
■
O -Other
Example
Console#traceroute 192.168.2.243
Press "ESC" to abort.