In message <0b215138-0162-4fe0-835a-9fc611a6e...@mac.com>, Chuck Swiger writes: > On Feb 14, 2012, at 2:59 AM, goran kent wrote: > > I need to setup an A record for a machine who's IP might change > > unexpectedly, and I need to ensure PCs out there cache it for as short > > a time as possible: > > > > host1 300 IN A 10.10.10.10 > > > > Does anyone know whether MS windows PCs will in fact honour that 300s, > > then force a re-lookup? Can I use even shorter values? eg, 60? > > ISC's BIND has (or had) a MINTTL value of 5 minutes / 300 seconds. > It's probably unreasonable to expect other platforms to refetch DNS > records faster than that.
To the best of my knowlege this is just plain wrong. If a answer had a TTL it was honoured. If a negative answer didn't have a TTL (no SOA record in the authority section) then one was choosen. > Aside from DNS, you're going to run into layer-2 problems with MAC-to-IP > mappings in your switches if you try to move an IP around at sub-minute > intervals. > > What problem are you actually trying to solve? It's likely that a tool > or mechanism like load-balancing onto a pool of boxes would provide a > much better solution than expecting to move a box around so rapidly.... > > Regards, > -- > -Chuck > > _______________________________________________ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe > from this list > > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
