Re: [cobalt-users] DNS: I can't get it right!

["E.B. Dreger" <eddy+public+spam@xxxxxxxxxxxxxxxxx>]

JG> Date: Wed, 15 Jan 2003 11:37:50 -0500
JG> From: Jason Gottschalk


JG> $origin heidebreicht.com.
JG> @       IN      SOA     ns.hosting4u.net. jason@xxxxxxxx (

Try:

    @       IN      SOA     ns.hosting4u.net. jason.syo.com.

The '@' symbol must be converted to '.' in the RNAME section of
the SOA.  What you currently have is erroneous.


JG>                                 2001051606              ; Serial
JG>                                 10800           ; Refresh, seconds
JG>                                 3600            ; Retry, seconds
JG>                                 604800          ; Expire, seconds
JG>                                 86400)          ; Minimum TTL, seconds
JG>                 IN      NS      ns.hosting4u.net.
JG>                 IN      NS      ns2.hosting4u.net.
JG>                 IN      MX      10 mail.heidebreicht.com.

So far so good.


JG> $ORIGIN heidebreicht.com.

The magic answer to your question is to delete:

                                    IN      A       209.15.182.23

and instead use one of the following:

                                    IN      A       216.241.219.36
    @                               IN      A       216.241.219.36
    heidebrecht.com.                IN      A       216.241.219.36

where 216.241.219.36 is the A RR for nitra.chevydealer.com.

Using '@' tells BIND to substitute the current $ORIGIN value.
Note that you CANNOT use a CNAME in this case... it simply is not
possible.

Why?  Ignoring newer DNSSEC extensions, a CNAME cannot coexist
with other RRTYPEs.  In your case, you have NS servers for the
heidebreicht.com zone, so you simply CANNOT have a CNAME for
heidebreicht.com in addition to the NS records.

If you wish to have heidebreicht.com automatically update when
nitra.chevydealer.com, you have a few choices:

* Let nitra.chevydealer.com maintain DNS for heidebreicht.com,
  and slave the zone from there.  (Yuck!)

* Run a script to update your DNS records based on nslookup or
  similar.  (Messy!)

* Use DNS protocol UPDATE.  (Requires a bit of work.)
  the overall safest.)

* Let [www.]heidebreicht.com go to your server, then use HTTP
  redirect to jump to nitra.chevydealer.com.  (Easiest.)

* Use a DNS server/service that can automatically track the A
  RR without requiring any of the above.  (Shameless plug for
  something we have in the works.)


JG> mail.heidebreicht.com.          IN      A       208.1.221.18
JG> www.heidebreicht.com.           IN      CNAME   nitra.chevydealer.com.

As others have suggested, CNAMEs are yucky.  The problem is... if
you use an A record and nitra.chevydealer.com changes, you're
left in the lurch, being forced to change DNS manually.  Yuck.


JG> *.heidebreicht.com.             IN      CNAME   nitra.chevydealer.com.

Why do you [think you] want a wildcard RR?


Eddy
--
Brotsman & Dreger, Inc. - EverQuick Internet Division
Bandwidth, consulting, e-commerce, hosting, and network building
Phone: +1 (785) 865-5885 Lawrence and [inter]national
Phone: +1 (316) 794-8922 Wichita

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