VMX-M random site to site VPN links failing -

[Volcomer]

We have 52 site to site VPNs to a VMX-M hub in Azure who were all doing fine upp until today. Now 6 of them are failing at any give time. If we restart the failing MX device, it connects and another random site link falls down.

The VMX has been restarted (from meraki dashboard), and the MX's all have VPN connections to the other hub at HQ, so the error looks to be located with the vMX: 

(top bar was a power outage at a site, and unrelated)

Any suggestions?

[GIdenJoe]

So you're 100% sure it are different sites each time the vMX restarts?
If there is a pattern please check at the branch locations if you have an intermittend VPN registry disconnections causing a less than stable VPN.

Else this is a good reason to have a support case open.

[Volcomer · Accepted solution]

Got a packet trace from Meraki support and took it to my ISP. It seems to have been an issue with a router close to Azures Oslo datacenter and we just got the unfortunate timing of restarting MXs just at the time the "bad" route got preferred by other locations. Bad router got fixed and problem went away. Just one of those things I guess.