Additional Tracer Features and  Diagnostics

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Also new for version 4.3.2 is the ability to issue user defined commands before and after the actual trace route is performed.  This may be useful if you would like to capture any data before the trace route is performed.  Commands entered after a traceroute is performed are intended as a diagnostic feature and therefore are only issued if the traceroute fails. 

 

Below shows these "pre" trace route commands are defined by through the list-variable PRE_TRACE_CMD_LIST.  If you do not want to send any pre trace route commands, just comment out all of these lines. 

 

lappend PRE_TRACE_CMD_LIST "show ip cef"

lappend PRE_TRACE_CMD_LIST "SLEEP 1.0"

lappend PRE_TRACE_CMD_LIST "PING"

lappend PRE_TRACE_CMD_LIST "ping 10.1.1.1"

 

 

Below shows these "post" trace route diagnostic commands are defined  through the list-variable DIAG_CMD_LIST.  If you do not want to send any diagnostic type commands after a traceroute fails, just comment out all of these lines.

 

lappend DIAG_CMD_LIST "show ip route"

lappend DIAG_CMD_LIST "SLEEP 1.0"

lappend DIAG_CMD_LIST "PING"

lappend DIAG_CMD_LIST "ping 10.1.1.1"

lappend DIAG_CMD_LIST "show ip route DST"

lappend DIAG_CMD_LIST "show ip eigrp neighbors"

lappend DIAG_CMD_LIST "show ip cef DST"

 

In addition to any cisco IOS commands, there are several special commands that the script understands when specified in the PRE_TRACE_CMD_LIST variable.  These special commands are CASE SENSITIVE.

 

Special Pre-Trace Commands

Description

PING

If the command PING (all capitals) is specified, a ping will be sent to the destination for the upcoming traceroute.  Note, the source IP address used for the ping will be the same one used for the traceroutes

SLEEP <number in seconds>

If the command SLEEP (all capitals) is specified, the script will delay, in seconds, the amount of time specified before issuing the next pre-trace command.

DST

Substitute the trace route destination IP address into this parameter.

Example: lappend PRE_TRACE_CMD_LIST "show ip route DST"

SRC

Substitute the trace route source IP address into this parameter.

Example: lappend PRE_TRACE_CMD_LIST "show ip interface brief | include SRC"

VRF

Substitute the trace route source IP address into this parameter.

Example: lappend PRE_TRACE_CMD_LIST "show ip route vrf VRF DST"

Note, this is only valid when using the tracer input file with support for vrfs (see tracer_vrf_template.txt)