Responses expected from Fastly's authoritative name servers

Network Services
1

I understand that Fastly provides authoritative name servers (e.g. <letter>.sni.global.fastly.net) that users can point their domains to with CNAME records.

I expect that <letter>.sni.global.fastly.net will usually respond to a DNS query with “a unicast address specific to a single POP location.” When does Fastly’s authoritative name servers not respond with said unicast address?

I tried making DNS queries to www.citationneeded.news, a Fast Forward member, with well-known DNS resolvers such as Google Public DNS and Quad9, and I usually got Fastly’s anycast addresses instead of a unicast address. Is this expected behavior?

2

Hey @stvnwn this is expected behavior. Our system is tuned to return the most performant option, which may result in different anycast vs. unicast addresses based on your physical location and the network conditions we measure in a given window.