Anycast
Also known as: anycast routing, IP anycast
Announcing the same prefix from multiple locations so each user reaches the nearest instance - used by DNS resolvers and CDNs.
In anycast, one IP prefix is originated from many physical sites at once. BGP naturally routes each user to the topologically closest instance, giving low latency and built-in resilience: if one site fails, routing shifts to another.
Public DNS resolvers (like 1.1.1.1 and 8.8.8.8) and CDNs rely on anycast. Because the same prefix legitimately originates from many places, anycast is a common benign cause of MOAS-like observations.
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