CRC errors detected !!!!

[HThiam]

Good afternoon, 

We have a stack (x 4) of Meraki MS210-48FP providing ethernet connectivity to LAN users. A couple of month ago some users have started reporting connectivity issues with dropped connections. Upon reviewing the dashboard, it has come to our attention that the affected interfaces are showing a high proportion of CRC errors (see below) 

CRC errors detected.

Detecting a very high number of CRC errors on port x

We have since swapped the cables on the identified ports (switch and client end) to remediate to the issue and it seemed to have made a difference, however we are observing more of those errors on other interfaces.  I have now started considering that this could be beyond just a physical problem. The end clients are mostly phones ( SIP-T54W ) and laptops attached to a docking station. 

Has anyone experienced something similar?

Any advice would be very much appreciated.

Thank you 

[RWelch · Accepted solution]

Have you tried the flowchart troubleshooting steps?

CRC Errors 

[RWelch]

Additionally, the dashboard includes the Root Cause Analysis (RCA) workflows assist in the remediation of alerts that arise so you can take look at the alerts and follow the steps mentioned in cases of these alerts.
Root Cause Analysis (RCA) - Alert Based Workflows 

[HThiam]

I will give that try and let you know . Thank You 

[HThiam]

Thanks for the valuable troubleshooting guides . Cabling test  has failed , so I guess that in order to pinpoint the root cause , I need to further test  with all the prescribed cable / port permutations  .  I  can't keep wondering why would the all those cable fail around the same  time . 

[alemabrahao]

Do you have a patch panel before these connections? The only problem I can think of is a physical problem or a hardware problem.

Are you running the latest firmware? Have you done any cable testing?

I would also recommend opening a support case.

https://documentation.meraki.com/MS/Monitoring_and_Reporting/Using_the_Cable_Test_Live_tool

[HThiam]

Thank you for the input . Yes we have a patch panel in between the clients and the switch. Yes I believe we are running the latest firmware version ( MS 17.1.2 / CS 15.21.1 ) . I have also performed the cable testing which indicates some FAILURE  but I find it odds that the errors are  just  randomly showing on so many interfaces ( counting 32 across the stack so far ) . 

[cmr]

The newer firmware versions do pick up more errors than the older ones, ports running at 100Mb instead of 1Gb for example.  So it may be that you had at least some of the problems before, but they weren't being so actively reported.  If you are seeing cable test failures from the switch tester, try a physical cable tester to confirm the fault is genuine, it usually is, but just to be sure. 

[rhbirkelund]

Clean the SFPs and fiber cables, with a Fiber Optic Cleaner.

[HThiam]

We are only using Ethernet , no SFPs are being used .