Cloudflare's exploration of "BGP zombies"—routes that become unexpectedly stuck in the Internet's Default-Free Zone due to missed or lost prefix withdrawals—delves into the complexity of how these zombies form and impact network operations. These zombies can lead to routing inefficiencies, like trapping packets in loops or causing them to take unnecessarily long paths, thus affecting network performance. The article explains the concept of path hunting, where routers search for the best path to a prefix, and how this process can lead to zombie creation, particularly when more-specific BGP prefixes are withdrawn. Cloudflare highlights the role of BGP path hunting and Minimum Route Advertisement Interval (MRAI) in exacerbating these issues, and details how zombies can occur between upstream ISPs or within a network, causing traffic disruptions. To mitigate these problems, Cloudflare suggests improvements such as better traffic forwarding and a multi-step draining process for customers using on-demand BGP functionality. They also advocate for the implementation of the BGP SendHoldTimer to combat routing bugs that lead to zombie creation. Cloudflare's efforts aim to enhance the stability and efficiency of Internet traffic management, ultimately contributing to a more reliable global network.