Dynamic IP & cache DNS

Cricket Liu cricket at menandmice.com
Mon Sep 10 22:54:21 UTC 2001


> Unfortunately, gratuitously-low TTLs are detrimental to the public
> DNS infrastructure. If a node is going to have a particular IP address
> continuously for, say, 24 hours, why force other nameservers to re-lookup
the
> name as often as every 60 seconds? In a more perfect world, of course, a
> dynamic client would set the TTL to *exactly* as long as it was going to
have
> the IP address, no more, no less. This is, of course assuming that it
knows
> exactly how long it is going to have that address, that nothing breaks,
etc.
> etc. In short, it's unrealistic.

Well, I suppose gratuitously low TTLs are *unnecessary*, but why are
they detrimental to the public DNS infrastructure?  If I made the TTL
on www.nxdomain.com's A RR five seconds, your name server might
query my name server as often as every five seconds, but what effect
does that have on any other name servers?  Or are you counting every
name server that might query mine as "the public DNS infrastructure"?

cricket

Men & Mice
DNS Software & Services
www.menandmice.com




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