View source for CCNP TSHOOT 642-832/Chapter 2

=Introduction to Troubleshooting Processes=
__TOC__
=Troubleshooting Methods=
==Defining Troubleshooting==
*'''Step 1:''' Problem Report
*'''Step 2:''' Problem Diagnosis
*'''Step 3:''' Problem resolution
=== Diagnosing a Problem===
{|border=1 ;style="margin: 0 auto; text-align: center;cellpadding="5" cellspacing="0"
|+ Diagnosing a Problem
|- bgcolor=lightgrey
! Step !! Description
|-
|'''Collect Information''' || A problem report often lacks sufficient information. Collect additional information from. fx. Network Management tolls or interviewing the user.
|-
|'''Examine Collected Information'''||Examine collected information. Fx. comparing to baseline information.
|-
|'''Eliminate Potential causes''' || Based on knowledge of network and collected information - start to eliminate causes.
|-
|'''Hypothesize Underlying Cause''' || After eliminating causes hypothesize the most likely cause of the problem.
|-
| '''Verify Hypothesis''' || Test if the hypothesize resolve the problem
|}
==The Value of a Structured Troubleshooting Approach ==
[[Image:TSHOOT kapitel 2 - 1.png|500px|thumb|none|Structured Troubleshooting Approach]] 
[[Image:TSHOOT Kapitel 2 - 2.png|500px|thumb|none|'''Shoot from the hip''' Troubleshooting Approach]]
==Popular Troubleshooting Methods==
[[Image:TSHOOT kapitel 2 - 3.png|800px|thumb|none|Top-down, Bottom-up or Divide and conquer approaches]]
[[Image:TSHOOT kapitel 2 - 4.png|600px|thumb|none|Follow the Path of Traffic]]
[[Image:TSHOOT kapitel 2 - 5.png|300px|thumb|none|Component Swapping]]
==Structured Troubleshooting Procedure==
By combining the previously mentioned Three-step troubleshooting procedure and the subprocesses of Problem Diagnosis steps you get
# Problem Report
# Collect Information
# Examine Collected Information
# Eliminate Potential Causes
# Hypothesize Underlying Cause
# Verify Hypothesize
# Problem resolution
=== Problem Report ===
*Often lacks information
*Are you authorized to resolve the problem or need to forward it.
*Interview the user who reported the problem.
=== Collect Information ===
*Collect information from routers and switches... (show debug commands, log, NMS etc)
=== Examine Collected information ===
*Identify indicators pointing to the underlying cause of the problem
*Find evidence that can be used to eliminate potential causes
Fin a balance between
*What ''is'' occurring on the network?
*What ''should be'' occurring on the network?

=== Eliminate Potential Causes===
*Is OSPF running etc. 
===Hypothesize Underlying Cause===
*If problem can't be resolved (Lack of authority, devices) a temporary fix could resolve the problem here and now.
===Verify Hypothesis ===
*Implementing the fix. (Make a plan)
===Problem resolution===
*Document the resolved problem.
=Including Troubleshooting in Routine Network Maintenance=
*Keep documentation up to date and reliable
==Maintaining Network Documentation==
*'''Require documentation''' - Make documentation a component in the troubleshooting flow. (get used to documenting)
*'''Schedule documentation checks''' - Routinely verify documentation.
*'''Automate documentation''' - Any configuration change on a device should be reflected in the documentation. (Compare)
==Establish a baseline==
<source lang=cli>
R1#<input>show processes cpu sorted 5min</input>
CPU utilization for five seconds: 5%/0%; one minute: 5%; five minutes: 5%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
 112     3719202   1028129       3617  0.15%  0.13%  0.15%   0 HRPC qos request
   4     2111767    304796       6928  0.00%  0.09%  0.06%   0 Check heaps
 139         232       304        763  0.15%  0.11%  0.05%   2 Virtual Exec
 142      554927   2283402        243  0.15%  0.10%  0.05%   0 IP Input
  34       57731  47158926          1  0.00%  0.02%  0.00%   0 RedEarth Tx Mana
   7      637306   3220477        197  0.15%  0.03%  0.00%   0 ARP Input
   6           0         2          0  0.00%  0.00%  0.00%   0 Timers
<notice> Output omitted... </notice>
</source>
==Communicating throughout the Troubleshooting Process == 
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|+Communicating throughout the Troubleshooting Process 
|- bgcolor=lightgrey
! Step !! Description
|-
|'''Problem Report''' || When a user report a problem. Communicate with the user to clarify the problem.
|-
|'''Collect Information''' || Collect information from for example a Service Provider. require communication. 
|-
|'''Examine Collected Information'''|| Communicate with other IT-staff
|-
|'''Eliminate Potential causes''' || Perhaps the troubleshooter communicate with a consultant.
|-
|'''Hypothesize Underlying Cause''' || The communication with other IT-staff helps to clarify the underlying problem.
|-
| '''Verify Hypothesis''' ||  Before making online network changes causing outlets. Notify users about the interruption. 
|-
| '''Problem Resolution''' || The user reporting the problem should be informed and the user confirm that the problem is resolved.
|}
==Change Management==
The process of Change Management includes using policies that dictate rules regarding how and when a change can be made and how that change is documented.
{{Source cli}}
[[Category:CCNPv6]][[Category:CCNPv6 TSHOOT]]