Keep in mind it is going to work top down.  If ISE finds a reference in the 1st domain it will try to authenticate it.  Does any type of trust exist between the 2 domains.  ISE deployments can support multiple certificate chains and profiles but each...

If you have enough VM resources  upgrading ISE using the Backup and Restore method always saves time and cuts down on risk without having to purge any data. https://www.cisco.com/c/en/us/td/docs/security/ise/3-1/upgrade_guide/HTML/b_upgrade_method_3_...

Meraki uses LLDP for automatic discovery of connected devices.https://documentation.meraki.com/zGeneral_Administration/Other_Topics/LLDP_Support_on_Cisco_Meraki_ProductsLLDP is enabled by default on all Meraki devices with varying degrees of support....