multiple CNAMEs

[Kevin Darcy]

LC's Nospam Newsreading Account wrote:

> I read in our Solaris 2.7 man pages for named the following sentence
> apropos the options in named.conf
>
>      multiple-cnames
>                If yes, then multiple CNAME resource records  will
>                be  allowed for a  domain name. The default is no.
>                Allowing multiple CNAME records is  against  stan-
>                dards  and is not recommended. Multiple CNAME sup-
>                port is  available because  previous  versions  of
>                BIND  allowed  multiple  CNAME  records, and these
>                records have been used for  load  balancing  by  a
>                number of sites.
>
> We are going to upgrade from BIND 4.x under Solaris 2.5. Does the above
> affect us in some form ? At the moment we do not use CNAME to refer to
> *domains*, but we use them to refer to hosts inside our domain.
>
> One case is this (taken from an organization-wide template)
>
> loopback-host   432000  CNAME   localhost
> loopback        432000  CNAME   localhost
> loghost         432000  CNAME   localhost
>
> A few others are of the form where a WWW server is aliased to a host
>
> wwwn            IN      CNAME   realhostname
>
> One defines a machine which handles outgoing mail from PCPine
>
> smtp            IN      CNAME   realhostname
>
> Another one defines the hosts to which printers are connected (or
> the network printer names)
>
> lp0host                 IN      CNAME           phaser
> lp1host                 IN      CNAME           adrastea
> lp2host                 IN      CNAME           lp2

No, those should be fine, since the CNAMEs all have different *owner* names,
even though some of them share the same *target* name.

"multiple-cnames" allows you to have multiple CNAMEs with the same owner
name (like if you had more than one CNAME record with the owner name
"smtp"), which is just plain evil, and never should have been allowed in the
first place IMO.


- Kevin