1. Cost: Cisco Firepower and Cisco Identity Services Engine (ISE) have different pricing models. Firepower is primarily a security and threat management solution that includes features such as next-generation firewalls, intrusion prevention systems, and advanced malware protection. The cost of Firepower solutions can vary depending on the specific features and licensing options required. On the other hand, Cisco ISE focuses on network access control and identity management. It helps enforce security policies and manage user access to network resources. The cost of ISE is typically based on the number of endpoints or users that need to be managed.
2. Functionality: Firepower and ISE differ in terms of their core functions and capabilities. Firepower is designed to protect networks from various types of threats by inspecting network traffic, identifying malicious activities, and taking proactive measures to mitigate risks. It includes features like firewalling, intrusion prevention, and threat intelligence. In contrast, ISE is primarily focused on managing network access based on user identities, device types, and policies. It provides capabilities for authentication, authorization, and accounting (AAA), as well as network segmentation and policy enforcement.
3. Deployment: Another key difference between Firepower and ISE is the way they are deployed. Firepower typically involves the installation of physical or virtual appliances that are placed at strategic points within the network. These appliances function as security gateways and can enforce security policies and perform threat detection and prevention. On the other hand, ISE is usually deployed as a centralized server that integrates with network infrastructure components such as switches, routers, and wireless controllers. It acts as a policy decision point and provides authentication and authorization services for network access control.
4. Integration: Firepower and ISE also differ in terms of their integration capabilities. Firepower integrates well with other Cisco security solutions and can be seamlessly integrated into existing security infrastructure. It can leverage threat intelligence feeds, security analytics platforms, and security management tools to enhance its capabilities. ISE, on the other hand, is designed to integrate with various network infrastructure components and management systems, including Cisco switches, routers, wireless controllers, and network management platforms. It provides an extensible framework for integrating with third-party solutions and protocols.
5. Scalability: Firepower and ISE have different scalability considerations. Firepower can scale horizontally by adding more appliances or virtual instances to handle increasing network traffic and security requirements. It can also leverage clustering and high availability configurations for resilience. On the other hand, ISE can scale vertically by deploying more powerful servers or by distributing the load across multiple servers in a distributed deployment model. It can handle large-scale deployments with thousands of endpoints or users.
6. Use Cases: Firepower and ISE are designed to address different use cases. Firepower is primarily aimed at securing networks against a wide range of threats and attacks, making it suitable for organizations that require advanced threat protection and network security. ISE, on the other hand, is focused on network access control and identity management, making it suitable for organizations that need to enforce access policies, manage user identities, and ensure compliance with security standards and regulations.

In summary, Cisco Firepower and Cisco Identity Services Engine differ in terms of cost, functionality, deployment, integration, scalability, and use cases. Firepower is a security and threat management solution, while ISE is focused on network access control and identity management.