unbound-anchor(8)               unbound 1.20.0               unbound-anchor(8)

       unbound-anchor - Unbound anchor utility.

       unbound-anchor [opts]

       Unbound-anchor  performs  setup  or update of the root trust anchor for
       DNSSEC validation.  The program  fetches  the  trust  anchor  with  the
       method from RFC7958 when regular RFC5011 update fails to bring it up to
       date.  It can be run (as root) from the commandline, or run as part  of
       startup scripts.  Before you start the unbound(8) DNS server.

       Suggested usage:

            # in the init scripts.
            # provide or update the root anchor (if necessary)
            unbound-anchor -a "/usr/local/etc/unbound/root.key"
            # Please note usage of this root anchor is at your own risk
            # and under the terms of our LICENSE (see source).
            # start validating resolver
            # the unbound.conf contains:
            #   auto-trust-anchor-file: "/usr/local/etc/unbound/root.key"
            unbound -c unbound.conf

       This  tool  provides  builtin  default contents for the root anchor and
       root update certificate files.

       It tests if the root anchor file works, and if not, and  an  update  is
       possible, attempts to update the root anchor using the root update cer-
       tificate.  It performs a https fetch of root-anchors.xml and checks the
       results  (RFC7958),  if  all checks are successful, it updates the root
       anchor file.  Otherwise the root anchor file is unchanged.  It performs
       RFC5011  tracking if the DNSSEC information available via the DNS makes
       that possible.

       It does not perform an update if the certificate  is  expired,  if  the
       network is down or other errors occur.

       The available options are:

       -a file
              The  root anchor key file, that is read in and written out.  De-
              fault is /usr/local/etc/unbound/root.key.  If the file does  not
              exist, or is empty, a builtin root key is written to it.

       -c file
              The  root  update certificate file, that is read in.  Default is
              /usr/local/etc/unbound/icannbundle.pem.  If the  file  does  not
              exist, or is empty, a builtin certificate is used.

       -l     List the builtin root key and builtin root update certificate on

       -u name
              The server name, it connects to https://name.   Specify  without
              https://  prefix.   The default is "data.iana.org".  It connects
              to the port specified with -P.  You can pass an IPv4 address  or
              IPv6 address (no brackets) if you want.

       -S     Do not use SNI for the HTTPS connection.  Default is to use SNI.

       -b address
              The source address to bind to for domain resolution and contact-
              ing the server on https.  May be either an IPv4 address or  IPv6
              address (no brackets).

       -x path
              The  pathname to the root-anchors.xml file on the server. (forms
              URL with -u).  The default is /root-anchors/root-anchors.xml.

       -s path
              The pathname to the root-anchors.p7s file on the server.  (forms
              URL  with  -u).   The default is /root-anchors/root-anchors.p7s.
              This file has to be a PKCS7 signature over the xml  file,  using
              the pem file (-c) as trust anchor.

       -n name
              The  emailAddress  for  the  Subject of the signer's certificate
              from the p7s signature file.  Only signatures from this name are
              allowed.   default  is dnssec@iana.org.  If you pass "" then the
              emailAddress is not checked.

       -4     Use IPv4 for domain resolution  and  contacting  the  server  on
              https.  Default is to use IPv4 and IPv6 where appropriate.

       -6     Use  IPv6  for  domain  resolution  and contacting the server on
              https.  Default is to use IPv4 and IPv6 where appropriate.

       -f resolv.conf
              Use the given resolv.conf file.  Not enabled by default, but you
              could try to pass /etc/resolv.conf on some systems.  It contains
              the IP addresses of the recursive nameservers to use.   However,
              since  this  tool could be used to bootstrap that very recursive
              nameserver, it would not be useful (since that server is not  up
              yet,  since  we  are bootstrapping it).  It could be useful in a
              situation where you know an upstream cache is deployed (and run-
              ning) and in captive portal situations.

       -r root.hints
              Use  the  given root.hints file (same syntax as the BIND and Un-
              bound root hints file) to bootstrap domain resolution.   By  de-
              fault a list of builtin root hints is used.  Unbound-anchor goes
              to the network itself for these roots, to resolve the server (-u
              option)  and  to check the root DNSKEY records.  It does so, be-
              cause the tool when used for  bootstrapping  the  recursive  re-
              solver,  cannot use that recursive resolver itself because it is
              bootstrapping that server.

       -R     Allow fallback from -f resolv.conf file to direct  root  servers
              query.   It  allows  you to prefer local resolvers, but fallback
              automatically to direct root query if they do not respond or  do
              not support DNSSEC.

       -v     More verbose. Once prints informational messages, multiple times
              may enable large debug amounts (such  as  full  certificates  or
              byte-dumps  of  downloaded  files).  By default it prints almost
              nothing.  It also prints nothing on errors by default;  in  that
              case  the  original root anchor file is simply left undisturbed,
              so that a recursive server can start right after it.

       -C unbound.conf
              Debug option to read  unbound.conf  into  the  resolver  process

       -P port
              Set  the  port  number to use for the https connection.  The de-
              fault is 443.

       -F     Debug option to force update of the root  anchor  through  down-
              loading  the xml file and verifying it with the certificate.  By
              default it first tries to update by contacting  the  DNS,  which
              uses  much  less bandwidth, is much faster (200 msec not 2 sec),
              and is nicer to the deployed infrastructure.  With this  option,
              it  still  attempts  to  do so (and may verbosely tell you), but
              then ignores the result and goes on  to  use  the  xml  fallback

       -h     Show the version and commandline option help.

       This  tool  exits with value 1 if the root anchor was updated using the
       certificate or if the builtin root-anchor was used.  It exits with code
       0  if  no update was necessary, if the update was possible with RFC5011
       tracking, or if an error occurred.

       You can check the exit value in this manner:
            unbound-anchor -a "root.key" || logger "Please check root.key"
       Or something more suitable for your operational environment.

       The root keys and update certificate included in this tool are provided
       for  convenience  and  under  the terms of our license (see the LICENSE
       file in the  source  distribution  or  https://github.com/NLnetLabs/un-
       bound/blob/master/LICENSE)  and  might be stale or not suitable to your

       By running "unbound-anchor -l" the  keys and certificate that are  con-
       figured in the code are printed for your convenience.

       The  build-in  configuration can be overridden by providing a root-cert
       file and a rootkey file.

              The root anchor file, updated with 5011 tracking, and  read  and
              written to.  The file is created if it does not exist.

              The  trusted  self-signed certificate that is used to verify the
              downloaded DNSSEC root trust  anchor.   You  can  update  it  by
              fetching  it  from  https://data.iana.org/root-anchors/icannbun-
              dle.pem (and validate it).  If the file does  not  exist  or  is
              empty, a builtin version is used.

              Source for the root key information.

              Signature on the root key information.

       unbound.conf(5), unbound(8).

NLnet Labs                       May  8, 2024                unbound-anchor(8)