Command Reference

trace

Use the trace privileged EXEC command to trace routes on a router configured with the ISO CLNS protocol.
trace
Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The trace command terminates when the destination responds, when the maximum time to live (TTL) is exceeded, or when the user interrupts the trace with the escape sequence. The information is encoded as follows:
hop-count name(nsap) result-of-probe
Sample Display

The following display shows an example of ISO CLNS trace output:
router# trace

Protocol [ip]: clns

Target CLNS address: thoth

Timeout in seconds [3]: 
Probe count [3]: 
Minimum Time to Live [1]: 
Maximum Time to Live [30]: 
Type escape sequence to abort.
Tracing the route to THOTH (55.0006.0100.0000.0000.0001.8888.1112.1314.1516)
      HORUS(55.0006.0100.0000.0000.0001.6666.3132.3334.3536) 32 msec  !  28 msec
28 msec  !
  2 IS-IS(55.0006.0100.0000.0000.0001.7777.2122.2324.2526) 56 msec  !  80 msec
56 msec  !
  3 THOTH(55.0006.0100.0000.0000.0001.8888.1112.1314.1516) 80 msec  !  80 msec  !  8
The following table describes the parameters that can be specified when using the trace dialog for CLNS:

Field Description

Protocol [ip]

The default protocol for trace is IP. You must specify CLNS to begin tracing a router on a CLNS router.

Target CLNS address

You can specify either an NSAP or host name.

Timeout in seconds

You can specify the length of time to wait after sending each probe before giving up on getting a response.

Probe count

You can specify the number of probes to be sent at each TTL level. The default is 3.

Minimum Time to Live [1]

You can set the TTL value for the first probes. The default is 1. Set to a higher value to suppress the display of known hops.

Maximum Time to Live [30]

You can set the largest TTL value that can be used. The default is 30. The trace command terminates when the destination is reached or when this value is reached.

The following table describes characters that can appear in ISO CLNS output:

Character Description

&

A time-to-live-exceeded error PDU was received.

U

A destination unreachable error PDU was received.

I

The user interrupted the test.

*

The probe timed out.

C

A congestion experienced packet was received.

Field	Description
Protocol [ip]	The default protocol for trace is IP. You must specify CLNS to begin tracing a router on a CLNS router.
Target CLNS address	You can specify either an NSAP or host name.
Timeout in seconds	You can specify the length of time to wait after sending each probe before giving up on getting a response.
Probe count	You can specify the number of probes to be sent at each TTL level. The default is 3.
Minimum Time to Live [1]	You can set the TTL value for the first probes. The default is 1. Set to a higher value to suppress the display of known hops.
Maximum Time to Live [30]	You can set the largest TTL value that can be used. The default is 30. The trace command terminates when the destination is reached or when this value is reached.

Character	Description
&	A time-to-live-exceeded error PDU was received.
U	A destination unreachable error PDU was received.
I	The user interrupted the test.
*	The probe timed out.
C	A congestion experienced packet was received.