Re: [Dnsmasq-discuss] misunderstanding negative caching
an ICMP no route to host or similar should cause option b) Simon. On 04/04/2019 22:25, Alex Litvak wrote: > Thank you for your reply Simon. If DNS service is down and dnsmasq > receive immediate icmp reject will this be a) cached, b) handled as > immediate error with next name server tried immediately, or c) just a > timeout within system defined time out? > > We are looking to avoid a delay with failing / overloaded DNS servers, > whence asking all those weird questions. > > Thanks again, > > On 4/4/2019 10:39 AM, Simon Kelley wrote: >> On 27/03/2019 00:32, alexander.v.lit...@gmail.com wrote: >>> Dear list, >>> >>> I configured dnsmasq with enabled negative cache and neg-ttl 600. I >>> attempted to use it with a query that times out (configured fake dns >>> servers >>> in the config file). When I ping a host, I have NXDOMAIN in logs. >>> However, >>> every time I ping it dnsmasq asks those servers to resolve the host. >>> Shouldn't I get rejection immediately based on dnsmasq negative cache? >>> >>> Thank you in advance, >>> >>> >>> >> >> A time-out will not be cached, which is generally sensible, I think. >> >> Simon. >> >> ___ >> Dnsmasq-discuss mailing list >> Dnsmasq-discuss@lists.thekelleys.org.uk >> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss >> > > > > ___ > Dnsmasq-discuss mailing list > Dnsmasq-discuss@lists.thekelleys.org.uk > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] misunderstanding negative caching
Thank you for your reply Simon. If DNS service is down and dnsmasq receive immediate icmp reject will this be a) cached, b) handled as immediate error with next name server tried immediately, or c) just a timeout within system defined time out? We are looking to avoid a delay with failing / overloaded DNS servers, whence asking all those weird questions. Thanks again, On 4/4/2019 10:39 AM, Simon Kelley wrote: On 27/03/2019 00:32, alexander.v.lit...@gmail.com wrote: Dear list, I configured dnsmasq with enabled negative cache and neg-ttl 600. I attempted to use it with a query that times out (configured fake dns servers in the config file). When I ping a host, I have NXDOMAIN in logs. However, every time I ping it dnsmasq asks those servers to resolve the host. Shouldn't I get rejection immediately based on dnsmasq negative cache? Thank you in advance, A time-out will not be cached, which is generally sensible, I think. Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] misunderstanding negative caching
On 27/03/2019 00:32, alexander.v.lit...@gmail.com wrote: > Dear list, > > I configured dnsmasq with enabled negative cache and neg-ttl 600. I > attempted to use it with a query that times out (configured fake dns servers > in the config file). When I ping a host, I have NXDOMAIN in logs. However, > every time I ping it dnsmasq asks those servers to resolve the host. > Shouldn't I get rejection immediately based on dnsmasq negative cache? > > Thank you in advance, > > > A time-out will not be cached, which is generally sensible, I think. Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] misunderstanding negative caching
Dear list, I configured dnsmasq with enabled negative cache and neg-ttl 600. I attempted to use it with a query that times out (configured fake dns servers in the config file). When I ping a host, I have NXDOMAIN in logs. However, every time I ping it dnsmasq asks those servers to resolve the host. Shouldn't I get rejection immediately based on dnsmasq negative cache? Thank you in advance, ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
