override ttl=0

[Stephane Bortzmeyer]

On Wed, Jan 02, 2008 at 08:50:55PM -0500,
 Kevin Darcy <kcd at chrysler.com> wrote 
 a message of 159 lines which said:

> Well, it *shouldn't* be included in BIND, in my opinion. If a DNS
> record comes from an authoritative source with TTL=0 then it is to
> be treated as highly dynamic,

On the other hand, many of these TTL=0 records are set up that way
because the administrator does not understand the DNS and irrationally
believes that he has no control of his data if the TTL is non-null (a
similar effect can be seen on the Web: many Web servers attempt to
disable caching because they do not understand it).

Can we ignore the fact that many high-traffic DNS recursors, such as
those of big ISPs, already incorporate such a patch, in order to
reduce the humongous amount of DNS traffic that comes from
ignorant-managed DNS zones?

If the "bumping" of the TTL is not done by default, is such a patch
really harmful?