Cisco Nexus Troubleshooting Dip Dive

Course details

Dip Dive into Nexus troubleshooting plus cat4500 tshoot & Cat3850 high cpu .

•Work towards turning initial problem description into platform specific problem description.

•Define "broken" and /or "not working"

•Understand how whatever is "not working" should be working

•Determine possible triggers, patterns, timestamps etc.

•Understand the topology when relevant

 "Initial" problem description: We're having protocol <x> changing states  intermittently

 "platform specific" / desired problem description: OSPF is flapping , only b/t these two specific links, not an issue on any other OSPF interfaces, and it looks as if box <x> stops transmitting hello packets from the CPU whenever it's being  polled by this SNMP device every 5 minutes.

Chapters:  

Nexus trobleshooting part 1 

Nexus trobleshooting part 2 

Nexus trobleshooting part 3 

Nexus trobleshooting part 4 

Nexus trobleshooting part 5 

Nexus trobleshooting part 6 

Nexus trobleshooting part 7 

Cat 4500 tshoot part 1 

Cat 4500 tshoot part 2 

Cat 4500 tshoot part 3

 Cat 3850 high cpu

• Contrary to popular belief…..

TAC esc, BU esc, DEs, TMEs, cs-nexus7000 do not have a magic wand to answer vague scenarios such as previous "initial" problem description.

•Hence the importance to get to a platform specific / component problem description.

•DEs that monitor the alias are not typically "network" troubleshooters, but are "feature" troubleshooters. So "escalating to DE/BU" is not a productive step unless the necessary info is gathered prior.

•Show techs are 'not' meant to simply be gathered and then passed to your direct escalation or alias.

 It is ok "not to  know" what you're looking for in every show tech.

 Utilize the knowledge you have about the problem (is a specific subnet , ip address, mac address, interface, or timestamp), and points in the show tech that have that data.