Bitcoin doesn't make outbound connections to multiple hosts sharing a /16 (there is some analogous prefix for IPv6 but I don't recall what it is). If you provi

Bitcoin doesn't make outbound connections to multiple hosts sharing a /16 (there is some analogous prefix for IPv6 but I don't recall what it is). If you provide it with a file containing a prefix trie that maps IPs to ASNs (or "enclosing ASN"-- e.g. merging any non-multihomed AS into its parent) then it won't make multiple outbound connections to the same ASN. There was some aspirations at some point of shipping a map file with the software, but I think the people working on that stopped working on Bitcoin. Gold standard would be if you were multihomed yourself, constructing such a map from your own routing tables that collapsed every ASN into its distinct parent such that no outbound peers share a common network at all. (Bitcoin nodes don't make many outbound connections, so this wouldn't be totally crazy). Though that would still be a little approximate because there is no guarantee that interdomain routing is symmetrical.