Notifying Caching Resolver of Zone Changes
Original Publication Date: 2004-Oct-11
Included in the Prior Art Database: 2004-Oct-11
There are a few implementations of a caching resolver daemon which caches, among other things, DNS responses. The caching daemon can sit on an individual system, to be used locally, or it can be used by multiple systems. Host records (A - address records, PTR-pointer records) on local DNS servers often changes readily. The DNS protocols specifies that a record can be cached for as long as the TTL(time to live). Unfortunately, when the DNS updates its host records, the caching daemon is unaware that its cached records might become invalid.