What security control would a border router typically implement?

A border router typically implements access control lists (ACLs) to manage traffic entering and exiting a network. ACLs are a fundamental security mechanism that help to filter network traffic based on predefined rules. By configuring ACLs, network administrators can allow or deny traffic based on criteria such as IP addresses, port numbers, and protocols. This capability is crucial for protecting the internal network from unauthorized access, while also enabling legitimate traffic to flow.

The use of ACLs allows the organization to block broad categories of traffic that may pose security risks, such as certain types of incoming connections or specific protocols that are not necessary for business operations. This approach helps to create a more secure perimeter around the network, reducing the attack surface that potential intruders can exploit.

While encryption protocols, VPN tunneling, and intrusion detection systems are all important aspects of network security, they serve different purposes. Encryption protocols are used to secure data in transit; VPN tunneling provides secure communication channels over public networks; and intrusion detection systems monitor and alert on suspicious activities. However, access control lists are specifically designed to enforce security policies at the network edge, making them a primary security control used by border routers.