It is only used for SD-WAN connectivity (and potentially client VPN).   This is the deployment guide.  I would recommend changing to "passthrough" mode before deployment. https://documentation.meraki.com/MX/MX_Installation_Guides/vMX_Setup_Guide_for_Microsoft_Azure  ... View more

No, the MX itself cannot be a Radius server, but you have some authentication options and even integration with AD. Follow the documentation.   https://documentation.meraki.com/MX/Access_Control_and_Splash_Page/Access_Control   https://documentation.meraki.com/MX/Content_Filtering_and_Threat_Protection/Configuring_Active_Directory_with_MX_Security_Appliances ... View more

Just an update; service provider did not provide us /29. What we did was to utilize the 2nd 4G uplink (MG21) so that MX1 gets two uplinks ( fiber + 4G) , and MX2 ends up with 1 uplink (4G). We made sure that both MX1/MX2 are connected to a LAN switch with trunk ports for keep alive mechanism. We dropped MX1 and failover worked.  ... View more