As part of our latest Cisco Meraki MS feature release, we’re pleased to announce support for warm spare failover in our layer 3 switch models—the MS320 and MS420 families. This brings high availability to our mission critical MS products through Virtual Router Redundancy Protocol (VRRP), ensuring that if a VRRP-enabled Meraki switch goes offline, a backup MS will immediately take over its gateway responsibilities.

How it works

During normal operation, both switches are online and respond to Layer 2 traffic. The primary switch, however, handles all Layer 3 network requests while the spare switch monitors its connection to the primary. Both primary and spare switches have unique IP addresses for management communication with the Meraki cloud (e.g., and, respectively, in the image below), but they also share a virtual IP address—serving as the gateway address for each IP subnet on the switch—for all non-management communication. From the point of view of other devices on the network, this shared virtual IP (vIP) is the default address for communication with the primary switch.

Other network devices send packets addressed to the virtual IP.

In the event the primary switch becomes unresponsive, the spare will immediately detect the change in connectivity and take over the primary switch’s Layer 3 responsibilities; it does this by responding to network requests addressed to the vIP. From the point of view of all other network devices, nothing has changed: they still communicate through the vIP, and have no knowledge that, from a physical standpoint, they are interacting with a new switch. Downtime and client disruption are minimized. Network alerting can be enabled to notify you that the primary switch is offline, keeping you informed that failover has occurred.

Configuring warm spare failover

Configuring an MS switch as a warm spare is easy: simply navigate to Configure > Layer 3 routing in the Meraki dashboard, and select the “Add new warm spare” button. Next, select primary and spare switches.

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Meraki MS warm spare functionality is easy to configure in the Meraki dashboard.

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Simply choose primary and spare switches from dashboard drop down lists.

Note that warm spare failover is only supported between Meraki switches within the same product family (e.g., MS320), though it’s not necessary to deploy the same model within a family. Warm spare failover cannot be configured between Meraki switches and non-Meraki peers.

Having warm spare failover for mission critical switches keeps outages from impacting resource availability on your network. We’re thrilled to offer warm spare failover on our Layer 3-capable switches, and encourage you to give us your feedback through our Make A Wish feature and via social media.