What is the process called that identifies attacking IP addresses and routes their traffic to a non-existent server?

The process that identifies attacking IP addresses and routes their traffic to a non-existent server is referred to as blackholing or sinkholing. In this technique, malicious traffic is effectively discarded by routing it to a "black hole," where it is absorbed and does not reach its intended target, thereby mitigating the impact of a Distributed Denial of Service (DDoS) attack or other forms of undesirable traffic.

This method serves as a proactive security measure to protect networks by ensuring that attackers' requests do not affect active services or overwhelm bandwidth. Blackholing can be particularly effective against known malicious IP addresses where traffic can be redirected without notifications to the attackers, thus masking the network’s real infrastructure.

Other options focus on different aspects of network security and management. An Intrusion Detection System is used to monitor network traffic for suspicious activity and potential threats but does not inherently redirect traffic. Traffic shaping involves managing bandwidth to ensure that network performance is optimized but is not specifically about redirecting or dropping malicious traffic. Packet filtering, meanwhile, refers to the examination of packets within a network to either allow or block them based on predefined security rules, but it does not necessarily involve routing traffic to a non-existent server.