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Ethernet Fabric (VDX, CNA)

Senior Member
Posts: 1
Registered: ‎04-24-2014

how to determine is ISL port is failing

I think the ISL connection between our two VDX7640s may be failing. Ran (1) Show fabric islports, (2) Show fabric ISL, (3) show process (mem, cpu, fan), and all passed. Running a ping test from my desktop and seeing occassional drops on switch 2 with concurrent high pings on switch 2 as if a reconnection is occuring. Reviewed ports on both switches for the ISL connection, no errors found.

Former Brocadian
Posts: 102
Registered: ‎02-04-2015

Re: how to determine is ISL port is failing

Hi CM,


From your post, I assume the path is Desktop > Switch1 > ISL > Switch2. Are you pinging an interface VE on switch 2?


You may check the raslog to see if the interface is flapping. If no signs of flapping and no errors/dropped packets on the ISL, then I don't think that the ISL is the issue here.


Try to hook a machine to Switch 2 and run a concurrent ping sessions: 1 to the switch itself, and the other towards the end device. You will end up with one of two possible outcomes: 


1) If you only see drops pinging Switch 2 but not the end host, then there is no physical issue here. Could be the switch CPU just busy responding to other traffic.


2) If you see loss towards both destinations (Switch and End host) then you will need to troubleshoot end to end and see where the drops are occurring. An ACL accounting will be the best way to count packets in and out.


Hope this helps addressing your issue.




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