Provided by: gdnsd_1.11.1-1_amd64 bug


       gdnsd-plugin-geoip - gdnsd meta-plugin for GSLB + failover via MaxMind's GeoIP databases


       Minimal example gdnsd config file using this plugin:

         plugins => { geoip => {
           maps => {
             my_prod_map => {
               geoip_db => GeoIPCity.dat,
               datacenters => [dc-03, dc-02, dc-01],
               map => {
                   EU => {
                       DE => [dc-03, dc-01],
                       CH => [dc-01, dc-03]
                   NA => { MX => [dc-02] }
             my_auto_map => {
               geoip_db => GeoIPCityv6.dat,
               datacenters => [dc1, dc2],
               auto_dc_coords => {
                  dc1 => [ 38.9, -77 ],
                  dc2 => [ 50.1, 8.7 ],
           resources => {
             prod_www => {
               map => my_prod_map
               service_types => default
               dcmap => {
                 dc-01 =>,
                 dc-02 => { lb01 =>, lb02 => },
                 dc-03 => [,, ]
             corp_www => {
               map => my_auto_map
               dcmap => {
                 dc1 =>,
                 dc2 =>

       Example zonefile RRs:

         www      600 DYNA geoip!prod_www
         www-dc01 600 DYNA geoip!prod_www/dc-01
         www.corp 600 DYNA geoip!corp_www


       gdnsd-plugin-geoip uses MaxMind's GeoIP binary databases to map address and CNAME results
       based on geography and (in the address case) monitored service availability.  It fully
       supports both IPv6 and the emerging edns-client-subnet standard.  If a request contains
       the edns-client-subnet option with a source netmask greater than zero, the edns-client-
       subnet information will be used instead of the source IP of the request (the IP of the
       querying cache).

       This plugin can operate in an automatic distance-based mode (using City-level coordinate
       information rather than an external file and a Region-level db).  It can also operate
       coordinate-free and rely on the user to configure a hierarchical map of cascading default
       user-location-to-datacenter mappings, starting at the continent level.

       The two modes can also be effectively mixed at geographic boundaries.

       For each "map" you define (which maps geographic location codes to preference-ordered
       lists of your datacenter locations), this plugin merges all of the raw GeoIP subnets into
       the largest possible supernets which contain identical responses in your configuration.
       These in turn are used to set larger edns-client-subnet scope masks than you'd see simply
       returning raw GeoIP results.


       The documentation for gdnsd-plugin-metafo(8) is required reading for understanding the
       geoip plugin documentation here.  The geoip plugin is an exact superset of the metafo
       plugin, and re-uses almost all of the metafo plugin's source code.  What plugin_geoip adds
       on top of the functionality of metafo is the ability to have the order of the datacenter
       failover list become dynamic per-request based on geographic hints derived from the
       client's network address, as well as the ability to do geographic selection of DYNC
       (CNAME) resources.


       The configuration of this plugin can reference several external configuration and/or data
       files.  The location of these files is dependent, of course, on whether the daemon is
       running in chroot or "system paths" mode.  In system paths mode, the directory for these
       files is commonly, e.g. /etc/gdnsd/geoip/ given autoconf $sysconfdir of /etc.  In chroot
       mode, the directory would be /srv/gdnsd/etc/geoip/ given a chroot directory of /srv/gdnsd.
       If any of the pathnames are specified as absolute paths, they will be taken literally
       (although this will still be relative to the chroot in the chroot case).


       The top level of the geoip plugin's configuration (i.e. "plugins => { geoip => { ... } }")
       supports only two special keys, both of which are required and expanded upon in detail in
       the next two sections: "maps", and "resources".  The "maps" section defines one or more
       named mappings of location information from GeoIP binary databases to ordered subsets of
       datacenter names.  The "resources" section defines one or more named resources, each of
       which references one of the named maps and resolves datacenter names to specific sets of
       addresses or CNAMEs.

       Any other keys present at this level will be inherited down inside of each per-resource
       hash inside the "resources" stanza, acting as per-resource defaults for anything not
       defined explicitly there.


       The "maps" stanza supports one special configuration key at the top level:

   "city_region_names = region_codes.csv"
       String, filename, optional.  GeoIP City databases use FIPS 10-4 codes for the names of
       Regions outside of the US and Canada, and two-letter national alpha codes within the US
       and Canada.  For example the Geneve region of Switzerland is identified as 07 in the
       database.  By default you would have to use these relatively confusing region codes in
       your hierarchical maps that make use of Region-level information (e.g. "EU => { CH => { 07
       => { Geneva => [ ... ] } } } }".  If this option is specified, it points to a text file
       that maps these FIPS codes to canonical, memorable full names for clearer map
       configuration (e.g. "EU => { CH => { Geneve => { Geneva => [ ... ] } } } }".  Note that
       while older versions of this data did not map the US/Canadian two-letter alpha codes,
       newer versions do (e.g. TX -> Texas).

       This setting does not affect the GeoIP "Region" -format databases, which have no region
       codes outside of the US and Canada, and always need the two-letter alpha codes in the map.

       The file format is a simple subset of the CSV format with 3 fields: ISO 3166-1 country
       code, FIPS 10-4 region code (or two-letter alpha in US/Canada), and the region name in
       double-quotes.  It is recommended you download this file directly from MaxMind's reference
       copy in this format.  As of this writing, it is available from them at the following URL:


       All other "maps"-level configuration keys are the names of the maps you choose to define.
       A map, conceptually, is a mapping between geography and/or network topology to varying
       ordered datacenter sub-sets.  The value of each named map must be a hash, and the
       following configuration keys apply within:

   "geoip_db = GeoIPv6.dat"
       String, filename, optional.  This is the filename of one of the supported MaxMind GeoIP
       database types.  It will be reloaded at runtime (without any significant query
       interruptions) if a change to the database file is detected.

   "geoip_db_v4_overlay = GeoIP.dat"
       String, pathname, optional.  This specifies an optional IPv4-level GeoIP database to
       overwrite the IPv4 sub-space of the IPv6 data loaded from "geoip_db".  It must be a
       V4-format database, and "geoip_db" must be defined as a V6-format database.  In all other
       respects, it is similar to "geoip_db".

       As of this writing, MaxMind doesn't sell a commercial GeoIPv6 database.  What they offer
       are free IPv6 GeoLite database downloads, which include the IPv4 subset in the less-
       accurate GeoLite form.  This option allows you to use these GeoLitev6 databases for IPv6
       coverage, and then overlay your paid commercial GeoIPv4 data on top for more accurate IPv4

   "datacenters = [ one, two, three, ... ]"
       Array of strings, required.  This is the total set of datacenter names used by this map.
       You must define at least one datacenter name (although 2 or more would be infinitely more
       useful).  At this time, there is a maximum limit of 254 datacenter names per map, although
       this could be raised if anyone requires it.  The order specified here is the fallback
       default result ordering in various default cases (e.g. if no explicit top-level map
       default list is given).

   "city_no_region = true"
       Boolean, default "false".  If this key is set to "true" and "geoip_db" references a City-
       level database, the Region-level information within it will be completely ignored for
       mapping purposes.  Your hierarchical map structure will now be "continent => country =>
       city" rather than "continent => country => region => city".

   "nets = { ... }"
       Key-value hash, optional (see below for alternate form).  If specified, the contents
       should be key-value pairs of "network/netmask" mapped to a datacenter name (or an array of
       datacenter names).  Any network-to-datacenter mappings specified here will override
       mappings determined via GeoIP.  Note that it is illegal to specify networks in the
       IPv4-like subspaces of IPv6 other than v4compat, but it is legal to specify actual IPv4
       networks (which are treated identically to v4compat).  See the section on IPv4 Compatible
       Addresses later in this document for more details.  The order of the networks is
       unimportant; they will always be sorted and inserted such that an entry which is a subnet
       of another entry is not obliterated by the parent supernet.

           nets => {
      => [ dc1, dc2 ],
      => dc3
               2001:DB8::/32 => [ dc4, dc5, dc6 ],

       In the case that one entry is a subnet of another with a different result dclist, the
       entries are merged correctly such that the supernet surrounds the subnet.  In the case of
       an exact duplicate entry (or an effective one, after merging smaller subnets) with a
       different dclist, it is arbitrary which one "wins" and the condition is warned about.  If
       you care about this case, you should sanitize your nets data beforehand with an external
       tool and/or parse for the warning message in log outputs.

   "nets = nets_file_name"
       String pathname, optional.  A variant of the above, but the contents of the key-value hash
       are loaded from the named external file.  This makes life easier for external tools and
       scripts generating large sets of nets entries (e.g. from BGP data).  The file will be
       monitored for changes and reloaded at runtime much like the GeoIP databases.

   "map = { ... }"
       Key-value hash, optional.  This is the heart of a named map which uses GeoIP: the map
       itself, which maps places to ordered lists of datacenters.  It requires that "geoip_db" is
       also specified, and makes no sense without it.

       This is a nested key-value hash.  At each level, the keys are location codes (continent,
       country, region, or city information depending on depth), and the values are either an
       ordered datacenter array (e.g. "[ dc03, dc01, dc04 ]"), or a sub-hash containing a deeper
       level of distinction.  At each layer, a special key named "default" is available, which
       sets the default for everything within the current scope.  The top-level default itself
       defaults to the ordered list from "datacenters" in the normal case.  If the entire "map"
       stanza is missing or empty, you just get the default behavior of "default".  A datacenter
       array can also be empty, which implies that this location is mapped to receive no response
       data (the server will still respond to the query, and will not issue an NXDOMAIN.  It will
       simply be a NODATA/NOERROR response like you'd get if there were no records of this type,
       but could be records of other types for the same name).

       The meaningful location keys at the top level are continent codes, of which there are
       primarily seven in MaxMind's databases: "AF" for Africa, "AS" for Asia, "NA" for North
       America, "SA" for South America, "EU" for Europe, "OC" for Oceania, and "AN" for
       Antarctica.  There is also an eighth continent-level code which is, literally, "--".  This
       is a sort of fallback "no information available" continent code, and it contains the
       special country codes "A1", "A2", "O1", and "--", which represent Anonymous Proxies,
       Satellite Providers, Other, and Unknown, respsectively.

       The next layer (the sub-hash beneath any continent code) maps ISO-3166-1 2-letter country
       codes, which as with continents can map directly to datacenters, or to yet another
       recursive layer.

       The next two layers deep are for Region and City level information, only available from
       the Region and City type databases.  The Region database type only provides region
       information for the US and Canada, using the standard local 2-letter abbrevations (e.g. AB
       for Alberta, OK for Oklahama).  The City databases use those same region abbrevations for
       the US and Canada, but use either FIPS 10-4 2-letter codes or full region names for the
       rest of the world's regions (as detailed earlier in, and controlled by, the
       "city_region_names" option).

       The actual City names at the final layer appear to be encoded using some form of ISO8859-1
       and/or CP1252 character set in the databases themselves, and your map entries will have to
       match byte-for-byte in the case of non-ASCII characters.  May come up with a better
       solution for this down the road.

       There is also one other special key (aside from "default") available at all levels of the
       map hierarchy, a boolean named "skip_level", default "false".  If set within the
       hierarchical "map" at any layer, it causes the next layer of detail to be skipped for this
       portion of the map.  For example, setting this at the very top layer would mean that the
       top layer would contain country-level codes directly, without an enclosing continent-level
       hierarchy.  Setting it within a country would mean that city names are used directly
       within that country, without an intervening layer of region names.  This option is not
       aware of the "city_no_region" option, so e.g. setting that option and specifying
       "skip_level" at the country-level would result in no further information being available
       within that country (as "skip_level" would skip the remaining layer of city data).


       "City-auto-mode" is a special mode of operation that automatically maps out the world to
       your datacenters based on coordinate math, so that you don't have to manually construct a
       complex hierarchical "map".  It can still be mixed with "map" of course, allowing you to
       use auto-mode for only select geographic areas if you wish (or disabling it for select
       areas by specifying manual lists).  The key parameter is "auto_dc_coords", which enables

       "auto_dc_coords = { ... }"
           Key-value hash, optional.  If this option is specified, the whole map's basic mode of
           operation changes to "city-auto-mode".  The contents of the hash are a key for each
           datacenter named in "datacenters", with their values set to an array of "[lat, lon]"
           in decimal degree units.  When city-auto-mode is enabled by this, the following
           configuration-validation changes occur from the default, static-mapping mode: the
           loaded GeoIP database(s) are required be City-level databases, and the special keyword
           "auto" becomes a legal "datacenter list" in the "map" stanza.

           With city-auto-mode enabled, the top-level map "default" defaults to "auto", but can
           be overridden with a manual list.  For any location that maps to "auto", the
           coordinates specified here in "auto_dc_coords" will be compared with the coordinates
           from the City-level database(s) to determine an automatic distance-sorted datacenter

           If you omit one or more defined datacenters from the coordinate list in
           "auto_dc_coords", those datacenters will not be used in automatic results, but will
           still be available for manual use via "map" and/or "nets" entries.

       "auto_dc_limit = N"
           Unsigned integer, optional, default 3.  When city-auto-mode is in effect, this is the
           upper length limit for auto-generated lists.  3 is a reasonable default even if you
           have a considerably longer set of datacenters, as this provides a primary as well as
           two fallbacks.  Raising this to a large number in the presence of a long datacenter
           list will cause the set of unique result datacenter lists to increase rapidly, and
           thus reduce the optimization of the final result database for edns-client-subnet
           purposes.  It's really not worth raising this value in almost any case, unless you
           really need to handle more than 3 random datacenters going offline at the same time
           and still have clients fail elsewhere.  The value zero is treated as unlimited (highly

       Under city-auto-mode, when the top-level default is (explicitly or implicitly) "auto",
       there is still a fallback static ordering which is the whole ordered "datacenters" list,
       which is the normal static default "default" when not in city-auto-mode.  This fallback is
       used when no location information is available at all (e.g. IPv6 client vs IPv4 GeoIP DB,
       Anonymous Proxies, etc).


       A binary program "gdnsd_geoip_test" is included.  This can be used directly from the
       commandline, parses the relevant bits of your gdnsd config file for geoip map info, and
       then provides datacenter list results for IP address + map combinations supplied by the
       user.  Useful for debugging your maps and testing the mapping of client IPs.  It has a
       separate manpage gdnsd_geoip_test(1).


       Resource-level configuration within the "resources" stanza is nearly identical to the
       resources configuration of the metafo plugin, with all of the same basic behaviors about
       synthesizing or directly referencing the configuration of other plugins per-datacenter.
       Only the key differences will be covered here:

       ·   metafo's per-resource "datacenters" array is replaced with "map => mapname", which
           references one of the maps defined in the "maps" stanza, described in detail earlier.
           The set of defined datacenters in the "dcmap" stanza must match the total set of
           datacenters defined by the referenced map.

       ·   metafo's restriction to just address-based (DYNA) results is lifted.  If the per-
           resource sub-plugin configurations used by a geoip resource support CNAME (DYNC)
           results, then that geoip resource will also support DYNC results.  Because there is no
           DYNC monitoring, only the first datacenter from each datacenter sub-list in the "map"
           will be used for the result; there is no failover, only geographic differentiation.

       ·   For the common case of a single CNAME result per-datacenter, the CNAME data can be
           supplied directly as the singular string value of each datacenter in the "dcmap",
           without involving a sub-plugin at all.


       Both of the meta-plugins ("metafo" and "geoip") can reference their own as well as each
       others' resources by direct reference within a "dcmap", so long as a resource does not
       directly refer to itself.  This allows plugin-layering configurations such as geoip ->
       metafo -> weighted, or metafo -> geoip -> multifo, or even metafo -> metafo -> simplefo,

       Bear in mind that once you begin using inter-meta-plugin references, you could create a
       reference loop.  gdnsd does not currently detect or prevent such loops, and they will
       cause complete runtime failure when queried, probably by running out of stack space during

       Additionally, "geoip" can synthesize configuration for "metafo" resources, but the reverse
       does not hold; "metafo" cannot synthesize configuration for "geoip" resources.

IPv4 Compatible Addresses

       This plugin knows of five different relatively-trivial ways to map IPv4 addresses into the
       IPv6 address space.  These are shown below, with "NNNN:NNNN" in place of the copied IPv4
       address bytes:

          ::NNNN:NNNN/96        # v4compat - canonical form for this plugin
          ::FFFF:NNNN:NNNN/96   # v4mapped
          ::FFFF:0:NNNN:NNNN/96 # SIIT
          2001::NNNN:NNNN/32    # Teredo (NNNN:NNNN is xor'd with FFFF:FFFF)
          2002:NNNN:NNNN::/16   # 6to4

       All of this plugin's internal lookup databases are IPv6 databases, and any IPv4-like
       information is always stored in the v4compat space within these databases.  When doing
       runtime lookups all other v4-like addresses (raw IPv4 addresses, v4mapped, SIIT, Teredo,
       and 6to4) are converted to the canonical v4compat IPv6 representation before querying the
       internal databases.  The other representations (v4mapped, SIIT, Teredo, 6to4) are
       Undefined internally, and will never be referenced at lookup-time due to the v4compat
       conversion mentioned earlier.

       The "nets" stanza is not allowed to specify entries in the four undefined v4-like IPv6
       spaces (those other than v4compat).  Specify those networks as normal IPv4 networks or
       v4compat networks instead.  Legitimate IPv6 "nets" entries which happen to be a supernet
       of any v4-like spaces will *not* undely affect v4-like lookups.  There is no functional
       difference between v4compat and native v4 forms in "nets", e.g. "" and
       "::C000:0200/120" are completely identical.

       GeoIP databases that are natively IPv4-only get all of their data loaded into the v4compat
       space only.  For IPv6 GeoIP databases, by default we load the v4compat space directly
       (which is where MaxMind stores IPv4 data in their IPv6 databases), but ignore the
       v4mapped/SIIT/Teredo/6to4 spaces (some of which are empty in MaxMind's databases, and some
       of which simply alias the v4compat space).  When using an IPv6 GeoIP database combined
       with an IPv4 GeoIP overlay (geoip_db_v4_overlay config), the v4compat space of the IPv6
       database is also ignored on loading, and the direct IPv4 data from the IPv4 databasee
       takes its place.


       A relatively-maximal example config, showing the interaction of valid "maps" and
       "resources" sections:

         service_types => {
           xmpp_svc => { plugin => "tcp_connect", ... }
           www_svc => { plugin => "http_status", ... }
         plugins => {
           geoip => {
             maps => {
               city_region_names => fips_include,
               my_prod_map => {
                 geoip_db => GeoIPCityv6.dat,
                 geoip_db_v4_overlay => GeoIPCity.dat,
                 city_no_region => false, # default
                 datacenters => [us-01, de-01, sg-01],
                 map => {
                     # Hierarchy is Continent -> Country -> Region -> City
                     NA => {
                       US => {
                         skip_level => 1, # skip past region level
                         Dallas => [sg-01],
                     SA => [us-01, sg-01, de-01],
                     EU => {
                       default => [eu-01, us-01, sg-01],
                       CH => {
                         Geneve => {
                           Geneva => [sg-01],
                     AF => [eu-01, us-01, sg-01],
                     AS => [sg-01, eu-01, us-01],
                     OC => [sg-01, us-01, eu-01],
                 nets => {
            => [ eu-01 ],
                     2001:DB8::/32 => [ us-01 ],
               my_auto_map => {
                 geoip_db => GeoIPCityv6.dat,
                 geoip_db_v4_overlay => GeoIPCity.dat,
                 datacenters => [us-01, de-01, sg-01],
                 auto_dc_coords => {
                    us-01 => [ 38.9, -77 ],
                    de-01 => [ 50.1, 8.7 ],
                    sg-01 => [ 1.3, 103.9 ],
             resources => {
               prod_app => {
                 map => my_auto_map
                 # these two are inherited multifo config keys
                 #  for all of the dcmap below:
                 service_types => [www_svc, xmpp_svc],
                 up_thresh => 0.4,
                 dcmap => {
                   us-01 => {
                     lb01 =>,
                     lb02 =>,
                     lb03 =>,
                     lb01.v6 => 2001:DB8::1,
                     lb02.v6 => 2001:DB8::2,
                     lb03.v6 => 2001:DB8::3,
                   sg-01 => {
                     lb01 =>,
                     lb02 =>,
                     lb03 =>,
                     lb01.v6 => 2001:DB8::4,
                     lb02.v6 => 2001:DB8::5,
                     lb03.v6 => 2001:DB8::6,
                   de-01 => {
                     lb01 =>,
                     lb02 =>,
                     lb03 =>,
                     lb01.v6 => 2001:DB8::7,
                     lb02.v6 => 2001:DB8::8,
                     lb03.v6 => 2001:DB8::9,
               prod_cdn => {
                 map => my_prod_map,
                 dcmap => {
                   us-01 =>
                   sg-01 =>
                   de-01 =>

       Example zonefile RRs:

         app     600 DYNA geoip!prod_app  600 DYNA geoip!prod_app/us-01  600 DYNA geoip!prod_app/sg-01  600 DYNA geoip!prod_app/de-01
         content 600 DYNC geoip!prod_cdn


       gdnsd-plugin-metafo(8), gdnsd_geoip_test(1), gdnsd.config(5), gdnsd.zonefile(5), gdnsd(8)

       The gdnsd manual.


       Copyright (c) 2012 Brandon L Black <>

       This file is part of gdnsd.

       gdnsd is free software: you can redistribute it and/or modify it under the terms of the
       GNU General Public License as published by the Free Software Foundation, either version 3
       of the License, or (at your option) any later version.

       gdnsd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
       even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
       GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with gdnsd.  If
       not, see <>.