Classless CIDR delegation...
Joseph S D Yao
jsdy at tux.org
Sun Aug 16 04:08:19 UTC 2009
On Sat, Aug 15, 2009 at 06:59:03PM -0700, Gregory Hicks wrote:
...
> zone "96-28.55.139.64.in-addr.arpa" {
> type master ;
> file "db.96-28.55.139.64.in-addr.arpa" ;
> allow-update { none; };
> };
>
> This is my reverse zone:
>
> ----
> $ORIGIN .
> $TTL 3600
>
> 96-28.55.139.64.in-addr.arpa. IN SOA ns.hicks.net. hostmaster.ns.hicks-net.net ( 2009081502 ; serial
...
> 97.139.55.64.in-addr.arpa. IN PTR localhost. ; rtr.hicks-net.net.
> 98.139.55.64.in-addr.arpa. IN PTR localhost. ; fw.hicks-net.net.
> 99.139.55.64.in-addr.arpa. IN PTR mx.hicks-net.net ; mx.hicks-net.net.
> 100.139.55.64.in-addr.arpa. IN PTR young-one.hicks-net.net.
> 101.139.55.64.in-addr.arpa. IN PTR young.hicks-net.net.
> 102.139.55.64.in-addr.arpa. IN PTR kris.hicks-net.net. (laptop)
> 108.139.55.64.in-addr.arpa. IN PTR metis.hicks-net.net.
> ----
>
> I have tried this variant on the PTR record. (There were others but I
> cannot remember them.) Anyway, all failed.
>
> 97.96-28.139.55.64.in-addr.arpa. IN PTR localhost.
...
Mr. Hicks,
The inconsistency between the order of the numbers in the IP address
fields of
96-28.55.139.64.in-addr.arpa. IN SOA ns.hicks.net. hostmaster.ns.hicks-net.net ( 2009081502 ; serial
and
97.96-28.139.55.64.in-addr.arpa. IN PTR localhost.
has already noted. Otherwise, the above is the correct form, rather
than the first format.
I would try to reduce the use of "$ORIGIN" as a rule. Why use it at
all??? It is often used in examples just to show where the origin
currently is, but as the ARM points out, it need not appear in the
actual zone files. I would have:
=======================================================================
$TTL 3600 ; default positive TTL = 1 hour
@ IN SOA ns.hicks-net.net. hostmaster.ns.hicks-net.net. (
2009081502 ; serial
3600 ; refresh
900 ; retry
604800 ; expire (1 week)
3600 ; NEGATIVE TTL (1 hour)
)
IN NS ns.hicks-net.net.
IN NS ns0.xname.org.
IN NS ns1.xname.org.
; 96 IN PTR network.hicks-net.net.
97 IN PTR r.hicks-net.net.
98 IN PTR f.hicks-net.net.
99 IN PTR mx.hicks-net.net.
100 IN PTR young-one.hicks-net.net.
101 IN PTR young.hicks-net.net.
102 IN PTR kris.hicks-net.net. ; (laptop)
108 IN PTR metis.hicks-net.net.
; 111 IN PTR broadcast.hicks-net.net.
=======================================================================
Note particularly:
(1) Lack of $ORIGIN anywhere. This reduces complexity.
(2) Added comment to $TTL, correcting comment error on new line 8.
(3) Use of "@" (default origin) on line 3 to use origin from
named.conf [reducing complexity].
(4) Corrected MNAME (source name server) in SOA record on line 3.
(5) Added of "." to end of RNAME (e-mail address) on line 3.
(6) Broke line 3 into 3+4 just for readability.
(7) Corrected comment on line 8, NEGATIVE TTL. Too many zone files
have the old commentary, which was obsoleted by RFC 2308.
(8) Added a "." to end of ns1's name on line 13.
(9) Removed "A" record between lines 13 and 14 - there does not need to
be an IP address for the name "96-28.55.139.64.in-addr.arpa".
(10) Removed "MX" record between lines 13 and 14 - there is probably no
e-mail being sent to *@96-28.55.139.64.in-addr.arpa.
(11) I often add lines like ll. 15 & 23 just as delimiters.
Uncommented. Your choice.
(12) With no $ORIGIN, one can use the last field only of the IP
addresses in ll. 16-22.
(13) Don't PTR anything to "localhost." - either give it a reasonable
name or comment out the entire line. Use the full name in the
internal view, whichever you do. (ll. 16-17)
(14) Added "." to end of name on l. 18 and removed comment that is the
same as the name and therefore useless.
(15) Put a ";" before "(laptop)" on l. 21 - good comment but it needs to
BE a comment and not part of the PTR declaration.
Note also that the PARENT name server(s)
55.139.64.in-addr.arpa nameserver = ns1.megapath.net.
55.139.64.in-addr.arpa nameserver = ns2.megapath.net.
MUST have something very like:
"named.conf":
zone "55.139.64.in-addr.arpa" {
type master;
file "zone.64.139.55";
allow-update { none; };
};
"zone.64.139.55":
$TTL ...
@ IN SOA ...
IN NS ...
...
; delegate 64.139.55.96/28 to Mr. Hicks' name servers
96-28 IN NS ns.hicks-net.net.
IN NS ns0.xname.org.
IN NS ns1.xname.org.
96 IN CNAME 96.96-28
97 IN CNAME 97.96-28
...
110 IN CNAME 110.96-28
111 IN CNAME 111.96-28
Incidentally, the CNAME records can also be auto-generated by inserting
$GENERATE 96-111 $ CNAME $.96-28
I hope that this helps!
--
/*********************************************************************\
**
** Joe Yao jsdy at tux.org - Joseph S. D. Yao
**
\*********************************************************************/
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