ISE TACACS scaling question

[kgander]

I currently have a customer that is looking to move their TACACS with ACS to their ISE deployment. They have around 1500 devices that would make this transition. They are looking for some guidance on what the performance impact would be when TACACS is included in ISE. I have not be able to find anything for BU best practices regarding scaling and design with the use of this new feature in ISE 2.0. Can someone please lean in and let me know if the scaling has changed with this new feature or has it remained the same. “1 psn for every 20,000 endpoints”

[Aaron Woland · Accepted solution]

See here for general sizing:  ISE 2.0 TACACS+ Deployment & Sizing Guidance

The sizing guidance for Device Administration (TACACS+) is vastly different than for network access (RADIUS); because the use-cases are vastly different.  I describe the differences in my blog here:  RADIUS versus TACACS+ | Network World

-Aaron