round-robin using cnames

Kevin Darcy kcd at daimlerchrysler.com
Thu Aug 17 20:39:45 UTC 2000


devin at thecabal.org wrote:

> On 16 Aug 2000 18:58:58 -0700, Kevin Darcy <kcd at daimlerchrysler.com> wrote:
>
> > The only drawback of having multiple A records referring to the same address is
> > that it creates an ambiguity as far as reverse mappings are concerned -- e.g.
> > should the address map back to "name1" or "bobo"? But this is usually of no
> > consequence since multi-A-record names are generally for the consumption of
> > clients, and reverse-mappings generally for the consumption of servers (there
> > are exceptions to these generalities, of course). My homegrown maintenance
> > system here doesn't generate reverse records for multi-A-record names at all.
>
> If I'm understanding RFC 2181 10.2 correctly, you can just stick them all in,
> and a query for the PTR record will respond with all of the RRs, yes?

Yup.

> Which means that the application that can't deal with a list of RRs (as
> opposed to the just one that seems to be what everyone expects) isn't really
> dealing with the specs as written.

I'm not sure what you mean by "can't deal". All applications I know about only look
at the first entry in the list; this is arguably one way of "dealing" with
multi-valued PTR's, though perhaps suboptimal.


- Kevin





More information about the bind-users mailing list