This is the story of a one-afternoon hack that turned into a one-weekend hack. I woke up on Saturday with a silly idea: what would it be like to use content-defined chunking (CDC) and serve the chunks over DNS?

Huston describes a clever (ab)use of the DNS system to query the ASN-to-prefix mapping database. DNS is a global, replicated key-value store that is useful for much more than just mapping hostnames to IP addresses. See also this.