[discuss] Real world Impact of multiple roots

Wed Jan 29 19:25:36 UTC 2014

Hi,

This is what i meant by broken, that the scope of CNAME is not 
restricted to a single class.

I have been told that it is unfixable.

avri

On 29-Jan-14 14:14, Barry Shein wrote:
>
> Point of Information.
>
> The usual idea for running multiple DNS roots is to use the resource
> record class which is 2 bytes (so could support ~2^16 values, ~65,535
> co-existing roots!) and is currently always IN though Chaos and Hesiod
> are defined in the standards (old MIT experiments.)
>
> I assume this is what Avri is referring to as "schema" though perhaps
> not, she might be referring to something more general, but it's in the
> same spirit.
>
> THE TECHNICAL PROBLEM is that CNAMES don't have these classes.
>
> CNAMES define aliases so if you want example.com and www.example.com
> to point at the same address the typical way to do that is to make one
> the Address record and the other a CNAME, an alias to it.
>
> This may sound minor but operationally it would be a huge problem
> unless fixed. All sorts of things rely on CNAMEs.
>
> Of course that could be fixed -- add a class field to CNAME RRs, for
> example, encourage everyone to rework their zone files and software.
>
> SMOP (Simple Matter Of Programming.)
>
>
> Also, did anyone mention split-horizons? Ok then, split-horizons (it
> probably isn't wortwhile discussing.)
>