Both ISE server down and survival challenge in Meraki MR and MS

[Mateen Ahmad]

Hi team, how we can survive with minimum access to users if in case our both ISE nodes are down or not reachable in a very worst scenario.? we are using Meraki wireless and wired network.

Any suggestion please?  

[marce1000]

  - In a solid ISE deployment , and in a modern network ; that issue must be seen as avoided already , as in my own years of experience , it simply never happened and 'does not intend to do so' , because it was designed for that.
   If you want to proceed on that question you can find solutions but it will cost you lots of business time , that you will no longer
  have for other tasks ; as for instance show in :
                  https://community.cisco.com/t5/wireless-mobility-knowledge-base/automated-backup-ssid-with-eem-on-catalyst-9800-wireless/ta-p/3743838

                That being only an example.

 M.
                 

[Mateen Ahmad]

what will happen to the existing concurrent sessions in that scenario(if both nodes failed/down) ?

[ahollifield]

Nothing. Only new sessions are impacted. (Unless a re-auth timer is reached) or the endpoint disconnects, reboots, etc

[ahollifield]

No such thing as "open mode" on wireless.

On MS, you can use critical auth VLAN.