Which security feature allows for the definition of inbound and outbound traffic rules?

The correct answer is Network Access Control Lists (ACLs). Network ACLs are a vital component of network security that allow administrators to define rules for both incoming and outgoing traffic. These lists can specify whether specific IP addresses or ranges can access resources within a network or whether traffic can flow out of the network to the wider internet.

Each rule in an ACL can specify allowed or denied actions based on protocols, ports, and IP addresses. This granularity gives network administrators the flexibility to manage network security with precision, ensuring that only authorized traffic can enter or leave the network.

While firewalls serve a similar purpose by filtering traffic based on defined security rules, they are typically more sophisticated and can offer additional features like deep packet inspection and logging. Security groups are primarily used in the context of cloud services to manage permissions for resources, but they don’t operate at the level of inbound and outbound traffic rules as ACLs do. VPN connections are utilized for secure access to remote networks but do not define traffic rules themselves.

Understanding how Network ACLs work is crucial for anyone managing network security, especially in environments that require strict control over which traffic can enter or exit the network.