DNS OUTAGE AVOIDANCE METHOD FOR RECURSIVE DNS SERVERS

摘要

This disclosure describes systems, methods, and apparatus to protect users of the Internet from DNS outages. In particular, an outage avoidance system is provided that includes query processing, outage avoidance processing, and a local cache, all configured to extend the TTL of expired answers to DNS queries or to ignore the expiration of an answer's TTL value, and thereby provide the expired answer in response to a client request when a DNS server is unable to obtain an answer from a remote DNS server.