APIC cluster, 5 nodes, Multi Site

[Walter Dey]

Now we can have up to 5 APIC; can someone please explain, what happens, if in a Multisite: site A has 3 APIC's, site B has 2 APIC's; and site A fails completely !

site B would not have the quorum, which would require a 6. APIC in site B, to handle this case ?

[mikriple · Accepted solution]

Hey Walter,

I believe this article will answer a lot of your questions:

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/kb/b_kb-aci-stretched-fabric.html

You will always need to have a quorum which is (N/2+1) nodes active where N is the number of APICs that are communicating with each other and can support write operations. If you have 5 then you will need at least 3 active so in this instance you would need the 6th APIC as a backup to the site with the (N/2-1) nodes. 

Thanks,

Mike Ripley