On 05/02/2021 20.28, Brendan McKenna wrote:
Hi,
What's happening is that nscd (the Name Service Caching Daemon) is updating its cache entries. When you visit a web site, it makes a DNS request to look up the site. The response has a time-to-live value associated with it. When that exipres, nscd re-issues the request to update its cache, on the assumption that you will (eventually) make the same request again at some point in the future.
So, if you want to eliminate the repeated requests, just shut nscd down and/or don't start it in the future. That way, the only time(s) you will see DNS requests being made is when you are actually browsing to a site, and not later.
Even with nscd running, it will (eventually) stop refreshing the cache entries -- the size of the cache is finite, so if you make enough DNS requests, eventually the "older" ones will be removed from the cache to make room for information pertaining to more recently-requested information.
Or just tell nscd to not cache external names. But that may make your browsing slower. -- Cheers / Saludos, Carlos E. R. (from 15.2 x86_64 at Telcontar)