CREST Practitioner Security Analyst (CPSA) Practice

What does ingress filtering refer to?

1. Monitoring DNS queries

2. Filtering outbound traffic

3. Filtering inbound traffic

4. Analyzing web server performance

The correct answer is: Filtering inbound traffic

Ingress filtering specifically refers to the practice of filtering incoming traffic to a network. The primary goal of ingress filtering is to prevent unwanted or harmful data packets from entering a computer network or system. This method helps to enhance security by ensuring that only legitimate traffic, often from known sources or according to predefined rules, is allowed through the network's boundaries. In the context of network security, ingress filtering mitigates threats such as IP spoofing, where an attacker sends packets from a forged address, misleading the receiving system regarding the true source of the data. By implementing strict filtering rules at the network's perimeter, organizations can better protect their internal systems from external threats. The other options center on different aspects of network traffic management and do not pertain specifically to the filtering of incoming traffic, reinforcing the focus and importance of ingress filtering in maintaining network integrity and security.