WAN2 causing loss of connectivity

[Arthur_23]

Hi,

We are comissioning an MX67 with a primary fibre connection (WAN1) and a secondary LTE connection (WAN2).  WAN2 is via a Microtik LTE router in bridge mode.  The second LAN port on the Meraki is configured as WAN2

The primary fibre connection on WAN1 works fine.  But when we plug in the WAN2 it drops the connection on WAN1 and the device loses connectivity.  The error on the dashboard is Disabled gateway (bad connectivity).    Rebooting the Meraki with both WAN ports connected does not help, nor does rebooting the Microtik.  When we unplug WAN 2 the device comes back online.

The Meraki is in in graceful failover mode (not load balanced) with WAN 1 as the primary

So it doesn't like the connection to the LTE for some reason.  However, does anyone know why that would cause the device to lose connectivity on the primary fiber link?  I would have thought it would show an error on WAN2 but the device would still stay connected via the primary. 

TIA

[BrandonS]

Have you tried swapping connections and see if the trouble follows the ISP side or Meraki side?

[Arthur_23]

No I haven't but I will give it a try thanks.  Strangely the Microtik works OK when connected to their existing Ubiquiti USG.

I was just curious why a 'faulty' failover link would cause the whole device to lose connectivity and not just report itself as not functioning.

[BrandonS]

Some conflict presumably, but I agree it seems like incorrect behavior.  There is a post about this, with some links to more information here too: https://community.meraki.com/t5/Dashboard-Administration/Z3C-Disabled-gateway-bad-connectivity/m-p/1...

I'll be curious to hear what you discover.  Good luck.

[Johan_C]

Hello, Did you ever find the reason or a solution for this? @BrandonS 

[Johan_C]

I mean @Arthur_23