Some third-party vendors sell older Cisco appliances (like the 1121 or 1131 series) that come with ACS 5.4 pre-installed. The license for the software stays with the hardware. Ensure you get a from the seller.
Capped at 20,000 endpoints, whereas ISE can handle up to 500,000. Comparison: ACS 5.4 vs. Cisco ISE ACS5.4 last date of support - Cisco Community cisco acs 5.4 iso download
Some third-party vendors sell older Cisco appliances (like the 1121 or 1131 series) that come with ACS 5.4 pre-installed. The license for the software stays with the hardware. Ensure you get a from the seller.
Capped at 20,000 endpoints, whereas ISE can handle up to 500,000. Comparison: ACS 5.4 vs. Cisco ISE ACS5.4 last date of support - Cisco Community