1 / 5

Network Associates Sniffer Pro Bridge Topology Change Symptom

Network Associates Sniffer Pro Bridge Topology Change Symptom. Tool Calibration Series. The Technology Firm info@thetechfirm.com. Goal Or Objective. While troubleshooting, I noticed that I was getting “Spanning Tree Topology Change” when in fact there wasn’t any Spanning Tree issues.

eliot
Download Presentation

Network Associates Sniffer Pro Bridge Topology Change Symptom

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Network Associates Sniffer ProBridge Topology ChangeSymptom Tool Calibration Series The Technology Firm info@thetechfirm.com

  2. Goal Or Objective • While troubleshooting, I noticed that I was getting “Spanning Tree Topology Change” when in fact there wasn’t any Spanning Tree issues.

  3. How Do We Validate These Findings? Possible Theory. BUG, BUG, BUG!!!!@@#@#!!!! Vendor… That’s always the; • easiest ‘answer’ • most probable ‘answer’ • All of the above ;-) On a more serious note, there maybe a simpler solution to the message. Maybe I’m having a serious Spanning Tree problem and don’t know it - yet. Prove or Disprove Theory Lets look at some packets to assist in our investigation.

  4. Packet Never Lie.. • When you go through the trace we can see in packet number 2, that the source MAC address has changed. • When I look further into the trace I can also see some CISCO CDP packets. • How did this happen? What did this mean, a Cisco bug? The answer is much more simpler and a lot less dramatic: • The port in question was spanned to my port so I was seeing my BPDU and the spanned port’s BPDU.

  5. So What ?!? • Now the obvious question, “So is this ‘good’ or ‘bad’?”. • The answer unfortunately is ‘neither’, it’s just what you have to be aware of when mirroring/spanning ports. • To defend the vendor, how are they supposed to know how you would configure network gear when troubleshooting. • On a more realistic note, spanning/mirroring ports isn’t new and I believe that NAI should at least include this possibility in their Expert help screen. Moral of this story; • As always understand what you are doing, then understand what the tool is doing

More Related