Which of the following are used in a firewall to protect the entity's internal resources?

 Internet Protocol (IP) address restrictions are used in a firewall to protect the entity’s internal resources by allowing or denying access to specific IP addresses or ranges of IP addresses based on predefined rules. Remote access servers, Secure Sockets Layers (SSLs), and failover services are not directly related to firewall protection, but rather to other aspects of network security, such as authentication, encryption, and availability. References: CISA Review Manual (Digital Version), Chapter 5: Protection of Information Assets, Section 5.2: Network Security Devices and Technologies