What is the ideal deployment mode to use when you need to manage separate security policies for multiple customers on a Cisco ASA device?

Spanned cluster mode combines multiple ASAs into a single logical unit for scalability and redundancy, not for providing separate security policies to different customers on one device.

IRB (Integrated Routing and Bridging) mode is used in some networking devices to allow routing and bridging on the same interface, which is not relevant for multi-customer security policy separation on an ASA.

VRF (Virtual Routing and Forwarding) mode provides separate routing tables and forwarding instances but does not provide the comprehensive, independent firewall context separation that multiple context mode offers on an ASA.

Multiple context mode on a Cisco ASA allows a single physical ASA device to be partitioned into several independent virtual firewalls, called security contexts. Each context operates as a standalone device with its own security policies, interfaces, and administration, making it perfect for multi-tenant environments or managing separate security domains for different customers.