When building a global network, you start building out knobs (usually implemented as routing policies):
cost, packet loss, latency, maintenance, diversity, isolation, “special”
[Really funny analogy between anycast and toilets, caching and water supply]
After having developed routing policies, you start looking into anycast. One of the first services to be anycast is DNS.
Anycast scaling: vip, ecmp
Anycast considerations: how to monitor services? how to control users? how to handle transient network events?
