A little update on this after a chat with our Cisco TAM and one of the Cisco/Meraki Technical Solutions Managers.   Basically in October Cisco started rolled out an update to customer tenancies (Meraki Portal) to add the 'Degraded Ethernet Speed' Alert. While they had the data being reported previously they didnt have an alert for the circumstance. This has been rolling through each tenancy and as it hits yours, the alert got enabled and you started getting email about it. This explains the 'multiple cables failed on same time on the same day', your tenancy got the backend update..   So whereas there are some known bugs related to not negotiating at 1Gb (depending on the AP model) it is likely that other models without this bug are real 100Mbit negotiation issues, and they have advised that 50% of TAC cases are in fact faulty cables and has been confirmed. Basically, its you likely had the problem beforehand and had not noticed the slightly darker green switch port. My suggestion would be to confirm the models with the known bug via TAC case and if its not those models, do some detailed cable tests (not just a continuity test) and check they are up to scratch on quality. This nugget of information hasnt been advised clearly and does change the thinking depending on the AP model. We have a mix of both cases so are testing cables and doing RMA's.   HTH  ... View more

Not as yet. They are continually trying to get me to test and replace cables which yield no change which is getting unacceptable. I have escalated this to our Cisco TAM and they are engaging the larger team. They cant explain and keep ignoring that fact that multiple AP's across multiple sites all developed a 'cable problem' at the same second on the same day after admitting they have a known issue on the MR46. ... View more

Thought this might help - Meraki Support said today on the matter; "We have a known issue that is very similar, but raised specifically for MR46. Please allow me some time to reach put to out product specialist team explaining we are seeing the same issue in multiple models." ... View more