Meraki MX supports warm spare configured in bridge mode (transparent)?

[mwenstrom]

Hello, can we configure a pair of MX as warm spare (Active/Standby) when in passthrough (bridge/transparent) mode?

The following doc does not list it as not supported:

https://documentation.meraki.com/MX-Z/Networks_and_Routing/Passthrough_Mode_on_the_MX_Security_Appli...

Warm spare doc lists only Concentrator (one-armed) and NAT modes as supported:

https://documentation.meraki.com/MX-Z/Other_Topics/Warm_Spare

The following doc seems to say its only supported in VPN concentrator (one armed) or NAT modes

https://documentation.meraki.com/MX-Z/Deployment_Guides/VPN_Concentrator_Deployment_Guide

Any input appreciated! Thanks!

[PhilipDAth]

I don't know this answer.

I think this is only support when using the MX's for AutoVPN only (aka VPN concentrator mode).

[jdizzle]

I bet you could but in that mode it's basically an l2 bridge from WAN to LAN.

If you attach the WAN and LAN ports of two bridge mode MXes to the same respective segments you will have created a loop. You then have STP block one of the ports so only one link is effective.

Notably warm spare mode doesn't add any value as you get the same effect by just hooking up two different MXen. The stats are aggregated together, I suppose.