Multiple CNAME alternantive?

[Kevin Darcy]

On 8/19/2010 10:52 AM, Steve Arntzen wrote:
> I would like to resolve dns.ourdomain.com to a list of our DNS server
> names and possibly their IPs.
>
> As we use many DNS servers (and or views) for our different development
> environments, it would be very helpful for the developers to easily find
> the name and IP of the proper name server to use.
>
> EXAMPLE:
>
> A lookup for dns.ourdomain.com would result in:
>
> nsdev1.ourdomain.com    192.168.100.10
> nsdev2.ourdomain.com    192.168.100.11
> nstest1.ourdomain.com   192.168.100.12
> nstest2.ourdomain.com   192.168.100.13
> nsprod1.ourdomain.com   192.168.100.14
> nsprod2.ourdomain.com   192.168.100.15
> etc.
>
> I want to avoid using configuration exceptions and multiple CNAMEs.
> Does anyone have a "clean" alternative?
>
>    
If you really want a list of *names*, then you have a number of record 
types you could use, which have names in the RDATA part of the record, 
e.g. PTR, MX, SRV. PTR is probably the "purest" way to catalog a list of 
names, since it doesn't have any extraneous RDATA fields that you'd need 
to fill with "dummy" info, and also it benefits from label compression 
in responses.

I am *not* a fan of representing hostnames in TXT records, since those 
don't benefit from label compression, and also, they don't prevent the 
accidental inclusion of extraneous characters (although those 
validations can be performed by whatever tool(s) maintain the data in 
those records).

Resolver configs use IP addresses, not names. If you just want a list of 
*addresses*, then these can be enumerated in a round-robin A record. You 
can even apply sortlisting to that, if you want.

                                                                         
                                                                         
                                                             - Kevin