1MKRDNS(1)             User Contributed Perl Documentation            MKRDNS(1)
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NAME

6       mkrdns - MaKe Reverse DNS (auto generate PTR maps)
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SYNOPSIS

9       mkrdns [options] [configuration file]
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DESCRIPTION

12       mkrdns is a program designed to auto-generate reverse DNS maps (IN PTR
13       records).  Some programs already accompany the BIND source package that
14       will do this kind of thing on a single domain or network basis.  mkrdns
15       will read either a named.boot or named.conf file, figure out which
16       domains and networks to deal with, and then generate the reverse maps.
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18       You are deemed "in charge" of a network/domain if you are the primary
19       DNS for a reverse zone, or if you are either the primary or secondary
20       for a forward zone.  The exception to this rule is that the 127.*
21       network is not auto-generated due to the "1 IN PTR localhost." issue.
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OPTIONS

24       -debug           Print debugging information.  (this will
25                        print a LOT of information, be warned.)
26
27       -extension <ext> Append the given extension to the output
28                        files.  This is useful if you want to
29                        have the reverse maps generated, but want
30                        to check their contents before use.
31
32       -help            The help screen.
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34       -quiet           Turn off warning messages (multiple A
35                        records -> IP, etc.)  Good for scripts,
36                        but you probably want to check on what
37                        the warnings report.
38
39       -rootdir <path>  Specify the path to the root directory
40                        that named will be running in.  This
41                        will handle anyone using a chrooted
42                        environment for named.  Everything except
43                        the configuration file is assumed to be
44                        under the new root.
45
46       -version         Show mkrdns version information.
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CONFIGURATION FILE

49       mkrdns reads the standard BIND configuration files named.boot and
50       named.conf.  If you don't specify the full path to the file on the
51       command line, mkrdns assumes that one (or both) will exist in /etc and
52       will search for them.  If none are found, the program exits.  If one is
53       found, it is used.  If both are found, named.conf is used.
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DIRECTIVES

56       Think of directives as configuration options for mkrdns which are
57       simply comments to BIND.  The current directives are map, serialt,
58       skip, and skipzone.
59
60       Map allows you to map hosts to another network.  This was designed in
61       for the purpose of handling DNS for a subnet of a class C network which
62       you do not control.  (See the DNS & BIND O'Reilly and Associates book,
63       3rd Ed., pg. 215-218) Assume that you have 10.4.4.32/27 (ie: you have
64       the 32 IPs from 10.4.4.32 to 10.4.4.63 ...)  You want to do reverse
65       mappings for those IPs, but you don't control 4.4.10.in-addr.arpa.  How
66       do you do it?  The solution is to become the master for another zone
67       (such as 32.4.4.10.in-addr.arpa. or 32-63.4.4.10.in-addr.arpa.), and
68       CNAME the correct reverse pointers to the ones you're in charge of.
69       The format for the directive is:
70          map <network/mask> <new network>
71
72       Ex: map 10.4.4.32/27 10.4.4.32-63
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74       This maps all hosts between 10.4.4.32 and 10.4.4.63 to 10.4.4.32-63.32
75       to 10.4.4.32-63.63.
76
77       Serialt will change mkrdns's behavior with the serial number for
78       certain zones.  By default, the serial number is assumed to be in date
79       format (YYYYMMDDVV, year/month/day/version).  However, you can tell
80       mkrdns to treat the serial number as a regular number instead.  This
81       allows for more than 100 zone changes a day, and has a bit more
82       flexibility depending on the environment.  The format for the directive
83       is:      serialt <view> <zone> <format>
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85       <view> specifies which view should be used for the behavior change.  If
86       not specified, mkrdns assumes "default".  <zone> is either "default" or
87       the actual zone (ie: 0.0.0.10.in-addr.arpa).  <format> is either "date"
88       or "number".
89
90       Ex: serialt internal 1.168.192.in-addr.arpa number
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92       Skip forces mkrdns to ignore certain hosts/IPs via regular expression.
93       The concept is that there are some IN A records that you would like to
94       skip and not create a reverse entry.  Skip allows this. (for instance,
95       "foo IN A 10.4.4.32" and "mail IN A 10.4.4.32" both exist, but you want
96       to force foo as the reverse lookup and ignore mail.  The following
97       example can do this for you.)  Format:
98          skip <regular expression>
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100       Ex: skip ^mail
101
102       This will skip any host (or IP) that matches the "^mail" regular
103       expression.  The host is the FQDN, and the IP is before mapping (see
104       above).
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106       Skipzone forces mkrdns to ignore certain zones while processing the
107       named configuration file.  A possible use for this is where you have
108       "bar.com" and "bar.net", and both of them should have the same host
109       info (ie: foo.bar.com and foo.bar.net both have the same records.)  You
110       want "bar.com" to be the reverse lookup for the IPs used.  So set the
111       zone file setting to the same file (bar.zone), and then add "skipzone
112       bar.net".  NOTE:  The skipzone argument must match EXACTLY with the
113       zone name in the config file.  NOTE: You can specify multiple zones in
114       the same "skipzone" statement. (ie: "skipzone foo.com bar.com")  NOTE2:
115       If you are using views, the zone string must be in the format
116       "view:zone".  If a view isn't given, "default" is assumed.
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118       ignoreslaves tells mkrdns to ignore any forward slave domains in the
119       configuration.  This is useful if, for instance, you are master for
120       both a forward domain and reverse domain (say 168.192.in-addr.arpa)
121       which go together, but you also have slave domains with hosts in the
122       same reverse zone.
123
124       The format of a directive differs (sorry) between named.conf and
125       named.boot.  UNIX-style comments (the hash mark then the comment) are
126       allowed.
127
128   named.boot directives
129       Directives look like a comment, so the format is simply:
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131        ; mkrdns <directive type> <parameters>
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133   named.conf directives
134       To make directives more efficient with BIND 8, the format is slightly
135       different:
136
137        /* mkrdns
138           <directive type> <parameters>
139           ...
140        */
141

EXAMPLES

143       mkrdns -e new /etc/named.boot
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145       This will run mkrdns over the file /etc/named.boot.  Output files will
146       be generated as <name>.new (i.e.: if the PTR zone file is called
147       160.zone, the output will be 160.zone.new.)
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NOTES

150       I tend to use this script like a lint check.  i.e.: Edit the proper
151       zone files, then run mkrdns.
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153       As with most documentation, there are probably things that aren't
154       mentioned in the docs that the script does/assumes/etc.  I apologize
155       for any inaccuracies/omissions.  Let me know if there are any parts
156       that have an "issue", and I'll see if I can't straighten it out.
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ASSUMPTIONS

159       The <network>.zone reverse map files must already be created, be
160       uniquely specified in the configuration file, and have the appropriate
161       information (SOA/NS records, etc.) in there.  This script will strip
162       out any PTR records, and then add them back in.  (This means anything
163       like blank lines and comments will be moved to the top of the file.)
164       $ORIGIN and $INCLUDE are striped as of mkrdns 1.3.
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166       You must be at least a secondary for all domains which reference IP
167       networks for which you're responsible.  There is no means (currently at
168       least) to specify a PTR record for a non-existent A record, so this
169       script must have access to all A records that need to be "reversed".
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171       If you have more than 1 A record pointing to a specific IP, you can't
172       have both be the PTR record.  This script takes the first A record it
173       sees as the one used for the PTR record.  A warning is printed for any
174       additional entries.  (While the RFCs don't prohibit multiple PTR
175       records for the same IP, I have yet to find anyone who can give me a
176       good reason to do it.)
177
178       Map serial numbers default to be in YYYYMMDDVV format.  (YYYY = year,
179       MM = month, DD = day, VV = version (00-99).  This script will convert
180       your serial number to this format if it's not already.  I don't have
181       too many daily DNS changes, so the action for not being able to update
182       the serial number (ie: VV is at 99 and can't be increased) is to simply
183       exit.  If this is going to cause a problem for you, you can use the
184       serialt directive to specify a zone (or the default) should treat the
185       serial number as a number instead of using the date format.  Either
186       way, a problem will come up when the serial number reaches 4294967295
187       (max value), but that's another story.  (mkrdns will print a warning if
188       this is about to happen)
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AUTHOR

191       Theo Van Dinter <felicity@mkrdns.org>
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195perl v5.34.0                      2022-01-20                         MKRDNS(1)
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