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DNS Anycast Resilience: Root Servers

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The myth of 13 DNS servers

The internet often claims to run on 'just 13 DNS root servers'. The truth: there are 13 root server IP addresses (A through M root), but each is served by hundreds of physical servers worldwide via BGP anycast.

F-root alone has over 250 locations. Total root server instances: over 1,600 globally. The 13-address limit was an artifact of DNS UDP message size in 1997 — anycast was the engineering solution to break that constraint.

Packets in motion — click to inspect:

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