Common Troubleshooting Techniques?

[Flintstone]

Guys,

I recently completed Cisco (CCNP) troubleshooting training and wanted to discuss the techniques mentioned and possible other techniques that are used by our members?

Techniques that were covered:

1) Top Down - Work from the application layer in the OSI model down to the physical layer.
2) Bottom up - Work from the physical layer in the OSI model up to the application layer.
3) Divide and conquer - Start in the middle of the OSI layer (Network Layer) and then go up or down depending on the results.
4) Follow the path - Determine the path that packets follow through the network from source to destination and track the packets along the path.
5) Spot the differences - Compare devices or processes of the network that are operating correctly to devices and processes that are not operating as expected.
6) Move the problem - Physically move components and observe if the problem moves with the components or not.

Another method discussed was Shoot from the hip technique where if you were experienced/knowledgeable enough of the symptoms you could resolve the problem very quickly?  If this didn't work then you should start using the techniques listed above?

I personally use the Divide and conquer technique a lot using ping/traceroute.  Also the Move the problem technique sometimes.

Which ones do you use?

I will also run a poll to see which technique is used the most?

CheerZ

[Michael McNamara]

That's a great post Flintstone!

I would have to say that I also use the Divide and conquer technique the majority of the time. Although I've used every technique you've listed above more than once in my career. On some occasions one technique or another wouldn't work (no results) so I'd have to change gears and adapt in trying to overcome the problem or issue.

Example; I'm currently experiencing a very odd wireless performance problem at one of my larger hospitals. In this case though it's not the largest in terms of wireless yet I'm having some severe performance issues on the 2.4Ghz band. In this case I'm running out of options so I'm trying to Move the problem by replacing the wireless controller with a different version. I suspect when I'm complete that the performance problem will be gone - not a fix but additional information to help identify the root cause.

Cheers!

[Flintstone]

Thanks to all that voted 

It looks like the Divide and conquer technique was the most used by our members.

CheerZ

[Dominik]

as it is most of the times I would say it depends.......

I also used all techniques for hunting down problems in my career. In most cases it depends on your troubleshooting expirience for a particular problem.
I do most of the times the method "Shoot from the hip" depending on my exprience on a problem. This is the quick method for fixing problems, if that down´t work out
I start using "Follow the path" or "Move the problem".

But every issue is different and I think there is no general golden way that you can use all the time.

I also will go to the Cisco CCNP troubleshooting course, looking forward of the Cisco instructors opionion that.

Bye

[rameshtall]

Hi,

I tried Bottom Up many times and worked well. I never used Divide and Conquer, looks interesting i will use this method when i come accross issue.

Thanks
Ramesh