Global-Scale Anycast Network Management with Verfploeter

Abstract

Anycast has become a valuable tool for network operators. It plays a vital role in making the DNS root system globally highly available and resilient to stresses from e.g. DDoS attacks. Content delivery networks use it to direct clients to local caches, and to absorb attack traffic. Yet managing an anycast network is far from simple. Earlier work studying a DDoS attack on the DNS root system, for example, shows that even highly distributed anycast networks can be overwhelmed. To manage an anycast service, it is vital to know the catchment of points of presence (PoPs) of the service. In earlier work, we introduced "Verfploeter" a novel active measurement method to determine anycast catchments using ICMP messages. Unlike previously existing approaches, Verfploeter is unbiased, accurate and can be executed directly by the anycast operator without the need for external vantage points. We demonstrated the efficacy of Verfploeter on a testbed and small anycast service. In this paper, we take the next step and deploy Verfploeter on one of the world's largest anycast networks, the Cloudflare CDN with 192 PoPs worldwide. We perform real-world case studies on network planning (what happens when PoPs are switched on or off), troubleshooting (reachability issues of an anycasted prefix) and security (detecting spoofed attack traffic). These case studies show that Verfploeter is highly suitable for such a large-scale operation and gives operators vital insights that allow them to improve network management practices of their anycast service.

BGP Anycast Tuner: Intuitive Route Management for Anycast Services

“…Wei et al [27] show that while anycast routing is generally stable, a small number of routes sees persistent instability. De Vries et al [28] developed VERFPLOETER to measure anycast catchments and later deployed it in one of the largest global anycast CDNs [29]. McQuistin et al [30] analyze the impact of routing on anycast CDNs.…”

Tangled: A Cooperative Anycast Testbed

“…Anycast research can be carried out by using simulators [3] [6], testbeds [8] [27] [17] or anycast networks in production [30] [38]. Anycast simulations are used in specific cases when you need to study site load and swarm and mobile catchment behaviors, usually in mobile and wireless networks [39].…”

Improving Anycast with Measurements

“…Using these three case studies, we show that Verfploeter is highly suitable for such a large-scale operation and gives operators vital insights that allow them to improve network management practices of their anycast service. The work in this chapter will be published as a research paper [114].…”