Updated: 2021-01-27 20:40:50 CST +08

DNS Cache

Cache Policy on different OS



  • if DNS zone TTL < MaxCacheEntryTtlLimit, then DNS TTL is used
  • if DNS zone TTL > MaxCacheEntryTtlLimit, then MaxCacheEntryTtlLimit is used


https://stackoverflow.com/a/11021207/4810199 > On Linux (and probably most Unix), there is no OS-level DNS caching unless nscd is installed and running.


https://apple.stackexchange.com/questions/93949/how-long-does-the-dns-cache-last-in-mac-os-x > How long a DNS entry is cached typically depends on the TTL of that DNS record, which is configured by the DNS admin of the relevant hostname.