CoDNS has a bootstrapping problem, since it must resolve peer names in order to operate. In particular, when the local DNS service is slow, resolving all peer names before starting will increase CoDNS's start time. So, CoDNS begins operation immediately, and starts resolving peer names in the background, which greatly reduces its start time. The background resolver uses CoDNS itself, so as soon as a single working peer's name is resolved, it can then quickly help resolve all other peer names. With this bootstrapping approach, CoDNS starts virtually instantaneously, and can resolve all 350 peer names in less than 10 seconds, even for slow local DNS. A special case of this problem is starting when local DNS is completely unavailable. In this case, CoDNS would be unable to resolve even any peer names, and could not send remote queries. CoDNS periodically stores all peer information on disk, and uses that information at startup. This file is shipped with CoDNS, allowing operation even on nodes that have no DNS support at all.