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> I don't really know anyone except for very networking-focused people who can explain how anycast works to achieve the same thing. I'm not familiar with the c
by a1369209993 6y ago
> I don't really know anyone except for very networking-focused people who can explain how anycast works to achieve the same thing.
I'm not familiar with the crap the IETF et al have smeared on it, but in principle, it's very simple: each network vertex maintains a mapping from (blocks of) addresses to edges (and the neighbors on the other ends of each edge) moving closer to that address, such that the directed edges for any given address form a rooted directed graph (ie a tree) where the root is the host with that address. Anycast just relaxes the requirement that the latent directed graph for a anycast address form a single tree with a single root, and instead allows multiple trees and roots forming a exact cover of the network. Updates still try to find the neighbor with the shortest round-trip time, but now there can be multiple network vertices with RTT=0 (ie multiple servers with the same anycast address).
- a1369209993 6y ago> but in principle, it's very simple Er, very simple provided that you're already doing doing unicast routing, that is. There are plenty of complexities, they just almost all already exist even without any anycast addresses.
- parliament32 6y agoExactly, if you're already doing routing/advertisements anycast just boils down to "advertise from multiple places at once" and it basically just works. If you're not doing your own routing this isn't a conversation for you.