1. A computer-implemented method comprising: obtaining a first DNS query from a client computing device at a first DNS server, wherein the first DNS query is associated with a first requested resource and wherein the first DNS server is associated with a content delivery network service; obtaining a query IP address associated with the first DNS query at the first DNS server, wherein the query IP address is associated with the client computing device; obtaining, at the first DNS server from a data store, an identifier at least based on a portion of the obtained query IP address, wherein the data store includes at least one partial IP address to identifier mapping; and resolving the first DNS query based on the identifier.