cancel
Showing results for 
Search instead for 
Did you mean: 

Very high proportion of CRC errors Meraki Switch

Here to help

Very high proportion of CRC errors Meraki Switch

I have problems with Switch Meraki MS225 and MS410

 

My Network using MS410 is core switch and using MS225 is access switch connect across buildings with fiber optic cables. The Problem is port on MS410 used connect with MS225 is alert "Very high proportion of CRC errors Meraki Switch" on this port. Then port MS410 is disconnect to MS225 and MS225 light status change from white light to orange light.

 

Anybody have any experience troubleshooting CRC error issues.

 

Thank you very much 

 

 

Screen Shot 2562-03-25 at 10.02.02.png

Screen Shot 2562-03-25 at 10.37.47.png

 

11 REPLIES 11
Kind of a big deal

Re: Very high proportion of CRC errors Meraki Switch

This is basically telling you that you have a bad cable between the switches. Could be the SFP modules since that model FTLF1318P3BTL-C1 is showing as 'Finisar' which isn't a Meraki SFP. Or the fiber cable has some issues, but I would probably start with swapping out the SFP modules on both sides to ones that are Meraki products.
Nolan Herring | nolanwifi.com
TwitterLinkedIn
Kind of a big deal

Re: Very high proportion of CRC errors Meraki Switch

As @NolanHerring said. Likely a bad or dirty SFP, bad or dirty fiber or an overly bent fiber patch cable (they have a maximum bend radius).

Kind of a big deal

Re: Very high proportion of CRC errors Meraki Switch

Could also be a mismatch somewhere. Make sure that all equipment on that path is spec'd identically. I.e. if you're using multimode OM4, make sure the SFPs are multimode on both ends and make sure that the patch cable is multimode (ideally OM4) too. Similarly if you're using single mode, everything should be single mode. In your case it's the latter so everything should be single mode.

 

Lastly, it could also be that you're near or over the max distance for that cable/speed. Take a look at the distances mentioned here:

https://meraki.cisco.com/lib/pdf/meraki_datasheet_sfp.pdf

Here to help

Re: Very high proportion of CRC errors Meraki Switch

@NolanHerring @BrechtSchamp Thank you so much for the suggestions. I will check according to your suggestions.

Kind of a big deal

Re: Very high proportion of CRC errors Meraki Switch

What grade of fibre is using used between the buildings?  E,g. OS1, OS2, OM3, etc.  What colour jacket is on the fibre?

 

Kind of a big deal

Re: Very high proportion of CRC errors Meraki Switch

Also is this newly installed fibre, or has the fibre been installed been in for a while and used with other switches?

Here to help

Re: Very high proportion of CRC errors Meraki Switch

I recommend cleaning the SFP's and fiber connections with one of these before you get too technical with the troubleshooting.

 

https://www.amazon.com/One-Click-Fiber-Connector-Cleaner-Connectors/dp/B01G5KL35O

Getting noticed

Re: Very high proportion of CRC errors Meraki Switch

I have the same issue. Any updates ? 

Here to help

Re: Very high proportion of CRC errors Meraki Switch

In case i'm disconnect all port on switch and recheck physical port and cable. Then i'm reconnect one by one port for analyse CRC error. But after reconnected all port CRC error not happening again.
I think cause of issue is physical problems.
New here

Re: Very high proportion of CRC errors Meraki Switch

I have seen this issue multiple times now after reboots.  Whether it be a reboot after a firmware upgrade or a power outage.  Once it comes back up, the module ports will give that alert.  The first time I swapped the cable and figured it was hardware.  The next time I swapped two twinax cables, but thought it was odd that two would go out at the same time.  Since then I've noticed that the issue does only come up for us after power cycles.  Power cycling the port or re-seating the fiber cable usually does the trick.  

 

Aside from @nakarin , is anyone else noticing the same?

 

FORGOT TO MENTION: This actually happened to us this morning after the power in the building was being worked on and caused the switches to go down.

Highlighted
Building a reputation

Re: Very high proportion of CRC errors Meraki Switch

I had this issue with a MS320, and eventually the SFP ports failed.  I only discovered it due to power outages during a construction phase, and then some extensive troubleshooting.

Welcome to the Meraki Community!
To start contributing, simply sign in with your Cisco account. If you don't yet have a Cisco account, you can sign up.
Labels