What is the primary purpose of a software firewall?

• A. To filter traffic based on rules
• B. To block all traffic
• C. To replace firewall appliance
• D. To route traffic

Answer: (A)

Filtering traffic based on rules is the main function of a software firewall. It runs on a computer and enforces a security policy by examining each network connection and deciding whether to permit or block it, using rules that consider factors like IP addresses, ports, protocols, and application identities. This helps protect the host by allowing legitimate communication while blocking potentially harmful activity, and it can manage both inbound and outbound traffic. A software firewall is host-based, not designed to replace a firewall appliance at the network edge, and it does not route traffic; routing is handled by separate devices and software.