linux - Bind 9.2 server refuses to resolve CNAME from sub-zone

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I've got an old master nameserver
running Bind 9.2 and a newer slave running 9.8. Right now we've got a project going on
where we're essentially splitting a cloud in two and we're using subzones and CNAMEs to
keep our services running smoothly. However, the cranky old 9.2 server doesn't seem to
want to resolve the CNAMEs to the subzone and returns REFUSED: recursion requested but not available. On the other hand the 9.8 server serves the
requests just
fine.

Disclaimer: I
know these nameservers are horribly out of date, and even worse the one running 9.2's OS
is waaaaay out of support as well, so I'm not likely to find a reputable package to
upgrade it. The project immediately after this cloud split is rebuilding our DNS
servers/services from scratch.

How
can I get the older server to resolve these CNAMEs
properly?

`dig`
results

dig @ NS1 [Bind
9.2]

# dig foo.domain.com
            @ns1.domain.com

; <<>> DiG
            9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6_6.3 <<>> foo.domain.com
            @ns1.domain.com

;; global options: +cmd
;; Got
            answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id:
            5937
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL:
            0
;; WARNING: recursion requested but not available

;;
            QUESTION SECTION:
;foo.domain.com. IN A

;; Query time:
            116 msec

;; SERVER: 4.3.2.1#53(4.3.2.1)
;; WHEN: Fri Jul
            31 16:18:36 2015
;; MSG SIZE rcvd:
            48

dig @ NS2 [Bind
9.8]

# dig foo.domain.com
            @ns2.domain.com

; <<>> DiG
            9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6_6.3 <<>> foo.domain.com
            @ns2.domain.com

;; global options: +cmd
;; Got
            answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id:
            59986
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL:
            2
;; WARNING: recursion requested but not available

;;
            QUESTION SECTION:
;foo.domain.com. IN A

;; ANSWER
            SECTION:

foo.domain.com. 300 IN CNAME
            foo.sub.domain.com.
foo.sub.domain.com. 300 IN A
            5.6.7.8

;; AUTHORITY SECTION:
sub.domain.com. 300 IN NS
            ns1.domain.com.
sub.domain.com. 300 IN NS
            ns2.domain.com.

;; ADDITIONAL SECTION:
ns1.domain.com. 30
            IN A 4.3.2.1
ns2.domain.com. 30 IN A
            1.2.3.4


;; Query time: 80 msec
;; SERVER:
            1.2.3.4#53(1.2.3.4)
;; WHEN: Fri Jul 31 16:22:29 2015
;; MSG SIZE
            rcvd:
            161

Config

Below
are the config files for the servers, trimmed down to the bare
essentials.

NS1 [Bind
9.2]

options {

            recursion no;
 additional-from-auth no;
 additional-from-cache
            no;
 blackhole { bogon; };
 directory "/var/named";

            notify yes;

};
zone "domain.com" {
 type
            master;
 file "/var/named/domain.com.hosts";
 also-notify { 1.2.3.4;
            };
 notify yes;
};
zone "sub.domain.com" {
 type
            master;
 file "/var/named/sub.domain.com.hosts";


            also-notify { 1.2.3.4; };
 notify
            yes;
};

NS2
[Bind 9.8]

options {

            directory "/var/named";
 recursion no;

 blackhole{ bogon;
            };
 dnssec-enable yes;
 dnssec-validation yes;

            dnssec-lookaside auto;
};
zone "domain.com" {
 type
            slave;
 masters { 4.3.2.1; };
 allow-transfer { 4.3.2.1;
            };
 file
            "/var/named/slaves/domain.com.hosts";

};
zone
            "sub.domain.com" {
 type slave;
 masters { 4.3.2.1; };

            allow-transfer { 4.3.2.1; };
 file
            "/var/named/slaves/sub.domain.com.hosts";
};

domain.com.hosts

$ORIGIN
            .
$TTL 300 ; 5 minutes
domain.com IN SOA ns1.domain.com.
            servers.domain.com. ( ... )
 NS ns1.domain.com.
 NS
            ns2.domain.com.
$ORIGIN domain.com.
sub NS
            ns1.domain.com.
sub NS ns2.domain.com.
foo CNAME
            foo.sub

sub.domain.com.hosts

$ORIGIN
            .
$TTL 300 ; 5 minutes
sub.domain.com IN SOA ns1.domain.com.
            servers.domain.com. ( ... )
 NS ns1.domain.com.
 NS
            ns2.domain.com.
$ORIGIN sub.domain.com.

foo A
            5.6.7.8

class="post-text" itemprop="text">

class="normal">Answer

I tossed
this question at some smart dudes on IRC and got the
answer:

options {

            additional-from-auth yes;
 additional-from-cache
            yes;
}

Where
both were explicitly set to no in my
config.

href="http://www.zytrax.com/books/dns/ch7/queries.html#additional-from-auth"
rel="nofollow
noreferrer">http://www.zytrax.com/books/dns/ch7/queries.html#additional-from-auth

additional-from-auth and
additional-from-cache control the behaviour when zones have
additional (out-of-zone) data or when following CNAME or DNAME records. These options
are for used for configuring authoritative-only (non-caching) servers and are only
effective if recursion no is specified in a global options
clause or in a view clause. The default in both cases is yes. These statements may be
used in a global options or in a view clause. The behaviour is defined by the table
below:

And then
the table basically boils down to:

If
they're not both set to yes the type of query
referenced in this question is going to be refused more or less all the
time.

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