In message <alpine.lsu.2.00.1603011133020.1...@hermes-2.csi.cam.ac.uk>, Tony Finch writes: > Mark Andrews <ma...@isc.org> wrote: > > In message <20160229225356.56583.qm...@ary.lan>, "John Levine" writes: > > > > > > >You could apply the technique to any signed zone where you are not > > > >worried about not having instant visibility after adding a new name > > > >to the zone. > > > > > > I don't understand this. If I ask for foo.example and get NXDOMAIN, > > > and 10 ms later you add a record at foo.example, my negative answer is > > > cached for your SOA TTL is. > > > > For 99.999999999% of names you don't look them up unless you have > > a priori knowledge that the name exist. > > Having done this myself, I think there are several situations in which it > is common to look up a name shortly before adding it to a zone. e.g. you > expect a name to exist, whoops, fix the omission, then have to wait a TTL. > Or you are trying to come up with a domain name that hasn't already been > registered and you forget to send the query to the TLD servers instead of > the local cache.
Accidents vs doing it every time you add a new machine / service is very different proposition. > Can be quite annoying if the TTL is long. Even so, I like aggressive > negative cacheing. > > Tony. > -- > f.anthony.n.finch <d...@dotat.at> http://dotat.at/ > Forties, Cromarty, Forth, Tyne, Dogger, Fisher, German Bight, Humber: South, > veering west, 6 to gale 8, occasionally severe gale 9 in Forties and Fisher, > decreasing 4 or 5 for a time. Moderate or rough, occasionally very rough. > Occasional rain or snow, fog patches. Moderate or poor, occasionally very > poor. -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
