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nsd.conf(5)                        nsd 4.1.1                       nsd.conf(5)



NAME
       nsd.conf - NSD configuration file

SYNOPSIS
       nsd.conf

DESCRIPTION
       Nsd.conf  is  used  to configure nsd(8). The file format has attributes
       and values. Some attributes have attributes inside them.  The  notation
       is: attribute: value.

       Comments  start  with  #  and  last to the end of line. Empty lines are
       ignored as is whitespace at the beginning of  a  line.  Quotes  can  be
       used, for names with spaces, eg. "file name.zone".

       Nsd.conf  specifies  options  for the nsd server, zone files, primaries
       and secondaries.

EXAMPLE
       An example of a short nsd.conf file is below.

       # Example.com nsd.conf file
       # This is a comment.

       server:
            server-count: 1 # use this number of cpu cores
            database: ""  # or use "/var/nsd/db/nsd.db"
            zonelistfile: "/var/nsd/db/zone.list"
            username: _nsd
            logfile: "/var/log/nsd.log"
            pidfile: "/var/nsd/run/nsd.pid"
            xfrdfile: "/var/nsd/run/xfrd.state"

       zone:
            name: example.com
            zonefile: /var/nsd/etc/example.com.zone

       zone:
            # this server is master, 192.0.2.1 is the secondary.
            name: masterzone.com
            zonefile: /var/nsd/etc/masterzone.com.zone
            notify: 192.0.2.1 NOKEY
            provide-xfr: 192.0.2.1 NOKEY

       zone:
            # this server is secondary, 192.0.2.2 is master.
            name: secondzone.com
            zonefile: /var/nsd/etc/secondzone.com.zone
            allow-notify: 192.0.2.2 NOKEY
            request-xfr: 192.0.2.2 NOKEY

       Then, use kill -HUP to reload changes from master zone files.  And  use
       kill -TERM to stop the server.

FILE FORMAT
       There  must be whitespace between keywords. Attribute keywords end with
       a colon ':'. An attribute is followed by its containing attributes,  or
       a value.

       At  the  top  level  only  server:  and key: and pattern: and zone: are
       allowed. These are followed by their attributes or the start of  a  new
       server:  or  key:  or  pattern: or zone: clause. The zone: attribute is
       followed by zone options. The server: attribute is followed  by  global
       options for the NSD server. A key: attribute is used to define keys for
       authentication. The pattern: attribute is followed by the zone  options
       for zones that use the pattern.

       Files  can be included using the include: directive. It can appear any-
       where, and takes a single filename as an argument. Processing continues
       as  if  the text from the included file was copied into the config file
       at that point.  If a chroot is used  an  absolute  filename  is  needed
       (with  the  chroot prepended), so that the include can be parsed before
       and after application of the chroot (and the  knowledge  of  what  that
       chroot  is).  You can use '*' to include a wildcard match of files, eg.
       "foo/nsd.d/*.conf".  Also '?', '{}', '[]', and '~' work,  see  glob(7).
       If no files match the pattern, this is not an error.

   Server Options
       The  global  options  (if  not overridden from the NSD commandline) are
       taken from the server: clause. There may only be one server: clause.

       ip-address: <ip4 or ip6>[@port]
              NSD will bind to the listed ip-address.  Can  be  give  multiple
              times  to  bind multiple ip-addresses. Optionally, a port number
              can be given.  If none are given NSD  listens  to  the  wildcard
              interface. Same as commandline option -a.

       interface: <ip4 or ip6>[@port]
              Same   as   ip-address   (for   easy   of   compatibility   with
              unbound.conf).

       ip-transparent: <yes or no>
              Allows NSD to bind to non local addresses.  This  is  useful  to
              have  NSD listen to IP addresses that are not (yet) added to the
              network interface, so that it can answer  immediately  when  the
              address is added. Default is no.

       debug-mode: <yes or no>
              Turns on debugging mode for nsd, does not fork a daemon process.
              Default is no. Same as commandline option -d.

       do-ip4: <yes or no>
              If yes, NSD listens to IPv4 connections.  Default yes.

       do-ip6: <yes or no>
              If yes, NSD listens to IPv6 connections.  Default yes.

       database: <filename>
              By default /var/nsd/db/nsd.db is used.  The  specified  file  is
              used to store the compiled zone information. Same as commandline
              option -f.  If set to "" then no database is  used.   This  uses
              less  memory  but  zone updates are not (immediately) spooled to
              disk.

       zonelistfile: <filename>
              By default /var/nsd/db/zone.list is used. The specified file  is
              used  to store the dynamically added list of zones.  The list is
              written to by NSD to add and delete zones.  It is  a  text  file
              with  a  zone-name  and pattern-name on each line.  This file is
              used for the nsd-control addzone and delzone commands.

       identity: <string>
              Returns the specified identity when asked for CH TXT  ID.SERVER.
              Default  is the name as returned by gethostname(3). Same as com-
              mandline option -i.

       nsid: <string>
              Add the specified nsid to the EDNS section of  the  answer  when
              queried  with an NSID EDNS enabled packet.  As a sequence of hex
              characters or with ascii_ prefix and then an ascii string.  Same
              as commandline option -I.

       logfile: <filename>
              Log messages to the logfile. The default is to log to stderr and
              syslog (with facility LOG_DAEMON). Same  as  commandline  option
              -l.

       server-count: <number>
              Start  this  many NSD servers. Default is 1. Same as commandline
              option -N.

       tcp-count: <number>
              The maximum number of concurrent, active TCP connections by each
              server.  Default is 100. Same as commandline option -n.

       tcp-query-count: <number>
              The maximum number of queries served on a single TCP connection.
              Default is 0, meaning there is no maximum.

       tcp-timeout: <number>
              Overrides the default TCP timeout. This also affects zone trans-
              fers over TCP.

       ipv4-edns-size: <number>
              Preferred EDNS buffer size for IPv4.

       ipv6-edns-size: <number>
              Preferred EDNS buffer size for IPv6.

       pidfile: <filename>
              Use  the pid file instead of the platform specific default, usu-
              ally /var/nsd/run/nsd.pid.  Same as commandline option -P.

       port: <number>
              Answer queries on the specified port. Default  is  53.  Same  as
              commandline option -p.

       statistics: <number>
              If not present no statistics are dumped. Statistics are produced
              every number seconds. Same as commandline option -s.

       chroot: <directory>
              NSD will chroot on startup to the specified directory. Note that
              if  elsewhere in the configuration you specify an absolute path-
              name to a file inside the chroot, you have to prepend the chroot
              path.  That  way,  you  can  switch the chroot option on and off
              without having to modify anything else in the configuration. Set
              the  value  to  ""  (the empty string) to disable the chroot. By
              default "/var/nsd" is used. Same as commandline option -t.

       username: <username>
              After binding the socket, drop user privileges  and  assume  the
              username.  Can  be  username,  id or id.gid. Same as commandline
              option -u.

       zonesdir: <directory>
              Change the working directory to the specified  directory  before
              accessing  zone files. Also, NSD will access database, zonelist-
              file,  logfile,  pidfile,  xfrdfile,  xfrdir,   server-key-file,
              server-cert-file,  control-key-file  and control-cert-file rela-
              tive to this directory. Set the value to "" (the  empty  string)
              to   disable   the  change  of  working  directory.  By  default
              "/var/nsd/zones" is used.

       difffile: <filename>
              Ignored, for compatibility with NSD3 config files.

       xfrdfile: <filename>
              The soa timeout and zone transfer daemon in NSD  will  save  its
              state  to  this  file.  State  is read back after a restart. The
              state file can be deleted without too much harm, but  timestamps
              of  zones  will  be  gone.  If it is configured as "", the state
              file is not used, all slave zones are checked for  updates  upon
              startup.  For more details see the section on zone expiry behav-
              ior of NSD. Default is /var/nsd/run/xfrd.state.

       xfrdir: <directory>
              The zone transfers are stored here before they are processed.  A
              directory  is  created  here  that  is  removed  when NSD exits.
              Default is /var/nsd/run/xfr.

       xfrd-reload-timeout: <number>
              If this value is -1, xfrd will not trigger a reload after a zone
              transfer.  If  positive  xfrd will trigger a reload after a zone
              transfer, then it will wait for the number of seconds before  it
              will  trigger  a  new  reload.  Setting this value throttles the
              reloads to once per the number of seconds. The default is 1 sec-
              ond.

       verbosity: <level>
              This  value  specifies  the verbosity level for (non-debug) log-
              ging.  Default is 0. 1 gives  more  information  about  incoming
              notifies  and  zone  transfers.  2  lists soft warnings that are
              encountered.

       hide-version: <yes or no>
              Prevent NSD from replying with the version string on CHAOS class
              queries.

       log-time-ascii: <yes or no>
              Log  time  in  ascii, if "no" then in seconds epoch.  Default is
              yes.  This chooses the format when logging to file.  The  print-
              out via syslog has a timestamp formatted by syslog.

       round-robin: <yes or no>
              Enable  round  robin  rotation  of  records in the answer.  This
              changes the order of records in the answer and this may  balance
              load across them.  The default is off.

       zonefiles-check: <yes or no>
              Make  NSD check the mtime of zone files on start and sighup.  If
              you disable it it starts faster (less disk activity in case of a
              lot  of zones).  The default is enabled.  The nsd-control reload
              command reloads zone files regardless of this option.

       zonefiles-write: <seconds>
              Write changed secondary zones to their zonefile every N seconds.
              If  the  zone (pattern) configuration has "" zonefile, it is not
              written.  Zones that have received  zone  transfer  updates  are
              written  to  their zonefile.  Default is 0 (disabled) when there
              is a database, and 3600 (1 hour) when database is "".  The data-
              base  also commits zone transfer contents.  You can configure it
              away from the default by putting the config statement for  zone-
              files-write: after the database: statement in the config file.

       rrl-size: <numbuckets>
              This  option  gives  the size of the hashtable. Default 1000000.
              More buckets use more memory, and reduce the chance of hash col-
              lisions.

       rrl-ratelimit: <qps>
              The max qps allowed (from one query source). Default 200 qps. If
              set to 0 then it is disabled  (unlimited  rate),  also  set  the
              whilelist-ratelimit  to  0  to disable ratelimit processing.  If
              you set verbosity to 2 the blocked  and  unblocked  subnets  are
              logged.   Blocked queries are blocked and some receive TCP fall-
              back replies.

       rrl-slip: <numpackets>
              This option controls the number of packets discarded  before  we
              send  back  a SLIP response (a response with "truncated" bit set
              to one). 0 disables the sending of SLIP packets, 1  means  every
              query will get a SLIP response.

       rrl-ipv4-prefix-length: <subnet>
              IPv4 prefix length. Addresses are grouped by netblock.

       rrl-ipv6-prefix-length: <subnet>
              IPv6 prefix length. Addresses are grouped by netblock.

       rrl-whitelist-ratelimit: <qps>
              The  max  qps  for  query  sorts  for  a source, which have been
              whitelisted. Default 2000 qps. With the rrl-whitelist option you
              can  set  specific  queries to receive this qps limit instead of
              the normal limit.  With the value 0 the rate is unlimited.

   Remote Control
       The remote-control: clause  is  used  to  set  options  for  using  the
       nsd-control(8)  tool to give commands to the running NSD server.  It is
       disabled by default, and listens for localhost by default.  It uses TLS
       over  TCP  where  the server and client authenticate to each other with
       self-signed certificates.  The self-signed certificates can  be  gener-
       ated  with  the  nsd-control-setup tool.  The key files are read by NSD
       before the chroot and before dropping user permissions, so they can  be
       outside the chroot and readable by the superuser only.

       control-enable: <yes or no>
              Enable remote control, default is no.

       control-interface: <ip4 or ip6>
              NSD  will  bind  to  the  listed  addresses  to  service control
              requests (on TCP).  Can be given multiple times to bind multiple
              ip-addresses.   Use  0.0.0.0  and  ::0  to  service the wildcard
              interface.  If none are  given  NSD  listens  to  the  localhost
              127.0.0.1  and ::1 interfaces for control, if control is enabled
              with control-enable.

       control-port: <number>
              The port number for remote control service. 8952 by default.

       server-key-file: <filename>
              Path    to    the    server    private    key,    by     default
              /var/nsd/etc/nsd_server.key.   This  file  is  generated  by the
              nsd-control-setup utility.  This file is used by the nsd server,
              but not by nsd-control.

       server-cert-file: <filename>
              Path   to   the  server  self  signed  certificate,  by  default
              /var/nsd/etc/nsd_server.pem.  This  file  is  generated  by  the
              nsd-control-setup utility.  This file is used by the nsd server,
              and also by nsd-control.

       control-key-file: <filename>
              Path  to  the   control   client   private   key,   by   default
              /var/nsd/etc/nsd_control.key.   This  file  is  generated by the
              nsd-control-setup utility.  This file is used by nsd-control.

       control-cert-file: <filename>
              Path   to   the   control   client   certificate,   by   default
              /var/nsd/etc/nsd_control.pem.  This certificate has to be signed
              with the server certificate.  This  file  is  generated  by  the
              nsd-control-setup utility.  This file is used by nsd-control.

   Pattern Options
       The pattern: clause is used to denote a set of options to apply to some
       zones.  The same zone options as for a zone are allowed.

       name: <string>
              The name of the pattern.  This is  a  (case  sensitive)  string.
              The  pattern  names that start with "_implicit_" are used inter-
              nally for zones that  have  no  pattern  (they  are  defined  in
              nsd.conf directly).

       include-pattern: <pattern-name>
              The options from the given pattern are included at this point in
              this pattern.  The referenced pattern must be defined above this
              one.

       <&lt;zone option>&gt;: <value>
              The  zone  options  such as zonefile, allow-notify, request-xfr,
              allow-axfr-fallback, notify, notify-retry,  provide-xfr,  zones-
              tats,  and outgoing-interface can be given.  They are applied to
              the patterns and zones that include this pattern.

   Zone Options
       For every zone the options need to be specified in  one  zone:  clause.
       The  access  control  list  elements can be given multiple times to add
       multiple servers. These elements need to be added explicitly.

       For zones that are configured in the nsd.conf config  file  their  set-
       tings  are  hardcoded  (in an implicit pattern for themselves only) and
       they cannot be deleted via delzone, but remove  them  from  the  config
       file and repattern.

       name: <string>
              The name of the zone. This is the domain name of the apex of the
              zone. May end with a '.' (in FQDN notation). For example  "exam-
              ple.com",  "sub.example.net.". This attribute must be present in
              each zone.

       zonefile: <filename>
              The file containing the zone information. If this  attribute  is
              present  it  is used to read and write the zone contents. If the
              attribute is absent it prevents writing out of the zone.

              The string is processed so that one string can  be  used  (in  a
              pattern)  for a lot of different zones.  If the label or charac-
              ter does not exist the  percent-character  is  replaced  with  a
              period  for output (i.e. for the third character in a two letter
              domain name).

              %s is replaced with the zone name.

              %1 is replaced with the first character of the zone name.

              %2 is replaced with the second character of the zone name.

              %3 is replaced with the third character of the zone name.

              %z is replaced with the toplevel domain name of the zone.

              %y is replaced with the next label under the toplevel domain.

              %x is replaced with  the  next-next  label  under  the  toplevel
              domain.

       allow-notify: <ip-spec> <key-name | NOKEY | BLOCKED>
              Access  control list. The listed (primary) address is allowed to
              send notifies to this (secondary) server. Notifies from unlisted
              or  specifically  BLOCKED  addresses  are discarded. If NOKEY is
              given no TSIG signature is required.  BLOCKED  supersedes  other
              entries,  other  entries are scanned for a match in the order of
              the statements.

              The ip-spec is either a plain IP address (IPv4 or IPv6), or  can
              be   a   subnet   of   the   form  1.2.3.4/24,  or  masked  like
              1.2.3.4&255.255.255.0 or a range of the  form  1.2.3.4-1.2.3.25.
              A  port number can be added using a suffix of @number, for exam-
              ple 1.2.3.4@5300 or 1.2.3.4/24@5300 for  port  5300.   Note  the
              ip-spec  ranges  do not use spaces around the /, &, @ and - sym-
              bols.

       request-xfr: [AXFR|UDP] <ip-address> <key-name | NOKEY>
              Access control list. The listed address (the master) is  queried
              for AXFR/IXFR on update. A port number can be added using a suf-
              fix of @number, for example 1.2.3.4@5300. The specified  key  is
              used during AXFR/IXFR.

              If  the  AXFR  option is given, the server will not be contacted
              with IXFR queries but only AXFR requests will  be  made  to  the
              server.  This  allows  an  NSD secondary to have a master server
              that runs NSD. If the AXFR option is left out then both IXFR and
              AXFR requests are made to the master server.

              If the UDP option is given, the secondary will use UDP to trans-
              mit the IXFR requests. You should deploy TSIG when allowing  UDP
              transport,  to  authenticate notifies and zone transfers. Other-
              wise, NSD is more vulnerable for Kaminsky-style attacks. If  the
              UDP option is left out then IXFR will be transmitted using TCP.

       allow-axfr-fallback: <yes or no>
              This option should be accompanied by request-xfr. It (dis)allows
              NSD (as secondary) to fallback  to  AXFR  if  the  primary  name
              server does not support IXFR. Default is yes.

       notify: <ip-address> <key-name | NOKEY>
              Access  control  list. The listed address (a secondary) is noti-
              fied of updates to this zone. A port number can be added using a
              suffix  of  @number, for example 1.2.3.4@5300. The specified key
              is used to sign the notify.  Only  on  secondary  configurations
              will  NSD  be  able  to detect zone updates (as it gets notified
              itself, or refreshes after a time).

       notify-retry: <number>
              This option should be accompanied by notify. It sets the  number
              of retries when sending notifies.

       provide-xfr: <ip-spec> <key-name | NOKEY | BLOCKED>
              Access control list. The listed address (a secondary) is allowed
              to request AXFR from this server. Zone data will be provided  to
              the address. The specified key is used during AXFR. For unlisted
              or BLOCKED addresses no data  is  provided,  requests  are  dis-
              carded.   BLOCKED  supersedes  other  entries, other entries are
              scanned for a match in the order of the  statements.   NSD  pro-
              vides  AXFR  for  its  secondaries,  but IXFR is not implemented
              (IXFR is implemented for request-xfr, but not for provide-xfr).

              The ip-spec is either a plain IP address (IPv4 or IPv6), or  can
              be   a   subnet   of   the   form  1.2.3.4/24,  or  masked  like
              1.2.3.4&255.255.255.0 or a range of the  form  1.2.3.4-1.2.3.25.
              A  port number can be added using a suffix of @number, for exam-
              ple 1.2.3.4@5300 or 1.2.3.4/24@5300  for  port  5300.  Note  the
              ip-spec  ranges  do not use spaces around the /, &, @ and - sym-
              bols.

       outgoing-interface: <ip-address>
              Access control list. The  listed  address  is  used  to  request
              AXFR|IXFR  (in case of a secondary) or used to send notifies (in
              case of a primary).

              The ip-address is a plain IP address (IPv4  or  IPv6).   A  port
              number  can  be  added  using  a  suffix of @number, for example
              1.2.3.4@5300.

       zonestats: <name>
              When compiled with --enable-zone-stats NSD can  collect  statis-
              tics  per  zone.  This name gives the group where statistics are
              added to.  The groups are  output  from  nsd-control  stats  and
              stats_noreset.  Default is "".  You can use "%s" to use the name
              of the zone to track its statistics.  If not  compiled  in,  the
              option can be given but is ignored.

       include-pattern: <pattern-name>
              The  options  from the given pattern are included at this point.
              The referenced pattern must be defined above this zone.

       rrl-whitelist: <rrltype>
              This option causes queries of this rrltype  to  be  whitelisted,
              for  this  zone.  They  receive the whitelist-ratelimit. You can
              give  multiple  lines,  each  enables  a  new  rrltype   to   be
              whitelisted for the zone. Default has none whitelisted. The rrl-
              type is the query classification that the  NSD  RRL  employs  to
              make  different types not interfere with one another.  The types
              are logged in the loglines when a subnet  is  blocked  (in  ver-
              bosity  2).   The RRL classification types are: nxdomain, error,
              referral, any, rrsig, wildcard, nodata, dnskey, positive, all.

   Key Declarations
       The key: clause establishes a key for use in access control  lists.  It
       has the following attributes.

       name: <string>
              The  key  name.  Used to refer to this key in the access control
              list.

       algorithm: <string>
              Authentication algorithm for this key.

       secret: <base64 blob>
              The base64 encoded shared secret. It  is  possible  to  put  the
              secret: declaration (and base64 blob) into a different file, and
              then to include: that file. In this way the key secret  and  the
              rest  of  the configuration file, which may have different secu-
              rity policies, can be split apart.

NSD CONFIGURATION FOR BIND9 HACKERS
       BIND9 is a name server implementation with its own  configuration  file
       format, named.conf(5). BIND9 types zones as 'Master' or 'Slave'.

   Slave zones
       For a slave zone, the master servers are listed. The master servers are
       queried for zone data, and are listened to  for  update  notifications.
       In  NSD these two properties need to be configured separately, by list-
       ing the master address in allow-notify and request-xfr statements.

       In BIND9 you only need to provide allow-notify elements for  any  extra
       sources  of  notifications  (i.e.  the  operators),  NSD  needs to have
       allow-notify for both masters and operators.  BIND9  allows  additional
       transfer sources, in NSD you list those as request-xfr.

       Here is an example of a slave zone in BIND9 syntax.

       # Config file for example.org options {
            dnssec-enable yes;
       };

       key tsig.example.org. {
            algorithm hmac-md5;
            secret "aaaaaabbbbbbccccccdddddd";
       };

       server 162.0.4.49 {
            keys { tsig.example.org. ; };
       };

       zone "example.org" {
            type slave;
            file "secondary/example.org.signed";
            masters { 162.0.4.49; };
       };

       For NSD, DNSSEC is enabled automatically for zones that are signed. The
       dnssec-enable statement in the options clause is  not  needed.  In  NSD
       keys  are  associated  with  an  IP  address in the access control list
       statement, therefore the server{} statement is not needed. Below is the
       same example in an NSD config file.

       # Config file for example.org
       key:
            name: tsig.example.org.
            algorithm: hmac-md5
            secret: "aaaaaabbbbbbccccccdddddd"

       zone:
            name: "example.org"
            zonefile: "secondary/example.org.signed"
            # the master is allowed to notify and will provide zone data.
            allow-notify: 162.0.4.49 NOKEY
            request-xfr: 162.0.4.49 tsig.example.org.

       Notice  that the master is listed twice, once to allow it to send noti-
       fies to this slave server and once to tell the slave  server  where  to
       look for updates zone data. More allow-notify and request-xfr lines can
       be added to specify more masters.

       It is possible to specify extra allow-notify lines for  addresses  that
       are also allowed to send notifications to this slave server.

   Master zones
       For  a  master zone in BIND9, the slave servers are listed. These slave
       servers are sent notifications of updated and are  allowed  to  request
       transfer  of the zone data. In NSD these two properties need to be con-
       figured separately.

       Here is an example of a master zone in BIND9 syntax.

       zone "example.nl" {
            type master;
            file "example.nl";
       };

       In NSD syntax this becomes:

       zone:
            name: "example.nl"
            zonefile: "example.nl"
            # allow anybody to request xfr.
            provide-xfr: 0.0.0.0/0 NOKEY
            provide-xfr: ::0/0 NOKEY

            # to list a slave server you would in general give
            # provide-xfr: 1.2.3.4 tsig-key.name.
            # notify: 1.2.3.4 NOKEY

   Other
       NSD is an authoritative only DNS server. This means that it is meant as
       a  primary  or  secondary  server  for zones, providing DNS data to DNS
       resolvers and caches.  BIND9  can  function  as  an  authoritative  DNS
       server,  the configuration options for that are compared with those for
       NSD in this section. However, BIND9 can also function as a resolver  or
       cache.  The  configuration  options  that BIND9 has for the resolver or
       caching thus have no equivalents for NSD.

FILES
       /var/nsd/db/nsd.db
              default NSD database

       /var/nsd/etc/nsd.conf
              default NSD configuration file

SEE ALSO
       nsd(8), nsd-checkconf(8), nsd-control(8)

AUTHORS
       NSD was written by NLnet Labs and RIPE NCC joint team. Please see CRED-
       ITS file in the distribution for further details.

BUGS
       nsd.conf  is parsed by a primitive parser, error messages may not be to
       the point.



NLnet Labs                       Feb  3, 2015                      nsd.conf(5)