MX Offline Expected Behaviour - L3 service availbaility

[AndP_net]

Hello everyone,

I would like to understand the behavior of an MX67-68 in case of connectivity loss to the Meraki cloud. From the KB article here, it states that after 8 hours, the MX will reboot to attempt reconnecting to the cloud. However, I would like clarification on the following points:

1. During the first 8 hours, are all LAN services provided without interruption? Specifically, are L3 interfaces reachable, and does DHCP continue to function?

2. After these 8 hours, I expect a reboot of approximately 2-3 minutes. Once it reboots, do all LAN services—interfaces and DHCP—continue to operate without any discontinuity?

3. If connectivity is still not restored after another 8 hours, does this reboot process repeat without interruption to LAN services?

I have a full-stack Meraki infrastructure across multiple locations, and since the MX is my core L3 device, also providing DHCP, it's crucial that in the event of a WAN fault, it can still manage local traffic properly on the LAN side. Unfortunately, I haven’t yet been able to replicate this scenario in the lab.

Thank you!

[cmr]

@AndP_net I would expect 1 and 2 to be true and 3 will have the same 2-3 minute interruption as 2.

I had my home's WAN link go down for a few weeks and the LAN did work, though most modern devices rejected it as they also look for the internet!  I could still print though from a wired PC to a wireless printer.