kea/doc/guide/bind10-guide.txt

                                 BIND 10 Guide

Administrator Reference for BIND 10

   This is the reference guide for BIND 10 version 20120712.

   Copyright © 2010-2012 Internet Systems Consortium, Inc.

   Abstract

   BIND 10 is a framework that features Domain Name System (DNS) suite and
   Dynamic Host Configuration Protocol (DHCP) servers with development
   managed by Internet Systems Consortium (ISC). It includes DNS libraries,
   modular components for controlling authoritative and recursive DNS
   servers, and experimental DHCPv4 and DHCPv6 servers.

   This is the reference guide for BIND 10 version 20120712. The most
   up-to-date version of this document (in PDF, HTML, and plain text
   formats), along with other documents for BIND 10, can be found at
   http://bind10.isc.org/docs.

   --------------------------------------------------------------------------

   Table of Contents

   Preface

                1. Acknowledgements

   1. Introduction

                1.1. Supported Platforms

                1.2. Required Software at Run-time

                1.3. Starting and Stopping the Server

                1.4. Managing BIND 10

   2. Installation

                2.1. Packages

                2.2. Install Hierarchy

                2.3. Building Requirements

                2.4. Quick start

                2.5. Installation from source

                             2.5.1. Download Tar File

                             2.5.2. Retrieve from Git

                             2.5.3. Configure before the build

                             2.5.4. Build

                             2.5.5. Install

   3. Starting BIND10 with bind10

                3.1. Starting BIND 10

                3.2. Configuration to start processes

   4. Command channel

   5. Configuration manager

   6. Remote control daemon

                6.1. Configuration specification for b10-cmdctl

   7. Control and configure user interface

   8. Authoritative Server

                8.1. Server Configurations

                8.2. Data Source Backends

                             8.2.1. Data source types

                             8.2.2. Examples

                8.3. Loading Master Zones Files

   9. Incoming Zone Transfers

                9.1. Configuration for Incoming Zone Transfers

                9.2. Enabling IXFR

                9.3. Secondary Manager

                9.4. Trigger an Incoming Zone Transfer Manually

                9.5. Incoming Transfers with In-memory Datasource

   10. Outbound Zone Transfers

   11. Dynamic DNS Update

                11.1. Enabling Dynamic Update

                11.2. Access Control

                11.3. Miscellaneous Operational Issues

   12. Recursive Name Server

                12.1. Access Control

                12.2. Forwarding

   13. DHCPv4 Server

                13.1. DHCPv4 Server Usage

                13.2. DHCPv4 Server Configuration

                13.3. Supported standards

                13.4. DHCPv4 Server Limitations

   14. DHCPv6 Server

                14.1. DHCPv6 Server Usage

                14.2. DHCPv6 Server Configuration

                14.3. Supported DHCPv6 Standards

                14.4. DHCPv6 Server Limitations

   15. libdhcp++ library

                15.1. Interface detection

                15.2. DHCPv4/DHCPv6 packet handling

   16. Statistics

   17. Logging

                17.1. Logging configuration

                             17.1.1. Loggers

                             17.1.2. Output Options

                             17.1.3. Example session

                17.2. Logging Message Format

   List of Tables

   3.1. Special startup components

Preface

   Table of Contents

   1. Acknowledgements

1. Acknowledgements

   ISC would like to acknowledge generous support for BIND 10 development of
   DHCPv4 and DHCPv6 components provided by Comcast.

Chapter 1. Introduction

   Table of Contents

   1.1. Supported Platforms

   1.2. Required Software at Run-time

   1.3. Starting and Stopping the Server

   1.4. Managing BIND 10

   BIND is the popular implementation of a DNS server, developer interfaces,
   and DNS tools. BIND 10 is a rewrite of BIND 9 and ISC DHCP. BIND 10 is
   written in C++ and Python and provides a modular environment for serving,
   maintaining, and developing DNS and DHCP. BIND 10 provides a EDNS0- and
   DNSSEC-capable authoritative DNS server and a caching recursive name
   server which also provides forwarding. It also provides experimental
   DHCPv4 and DHCPv6 servers.

   This guide covers the experimental prototype of BIND 10 version 20120712.

1.1. Supported Platforms

   BIND 10 builds have been tested on (in no particular order) Debian
   GNU/Linux 6 and unstable, Ubuntu 9.10, NetBSD 5, Solaris 10 and 11,
   FreeBSD 7 and 8, CentOS Linux 5.3, MacOS 10.6 and 10.7, and OpenBSD 5.1.
   It has been tested on Sparc, i386, and amd64 hardware platforms. It is
   planned for BIND 10 to build, install and run on Windows and standard
   Unix-type platforms.

1.2. Required Software at Run-time

   Running BIND 10 uses various extra software which may not be provided in
   some operating systems' default installations nor standard packages
   collections. You may need to install this required software separately.
   (For the build requirements, also see Section 2.3, “Building
   Requirements”.)

   BIND 10 requires at least Python 3.1 (http://www.python.org/). It also
   works with Python 3.2.

   BIND 10 uses the Botan crypto library for C++
   (http://botan.randombit.net/). It requires at least Botan version 1.8.

   BIND 10 uses the log4cplus C++ logging library
   (http://log4cplus.sourceforge.net/). It requires at least log4cplus
   version 1.0.3.

   The authoritative DNS server uses SQLite3 (http://www.sqlite.org/). It
   needs at least SQLite version 3.3.9.

   The b10-ddns, b10-xfrin, b10-xfrout, and b10-zonemgr components require
   the libpython3 library and the Python _sqlite3.so module (which is
   included with Python). Python modules need to be built for the
   corresponding Python 3.

1.3. Starting and Stopping the Server

   BIND 10 is modular. Part of this modularity is accomplished using multiple
   cooperating processes which, together, provide the server functionality.
   This is a change from the previous generation of BIND software, which used
   a single process.

   At first, running many different processes may seem confusing. However,
   these processes are started, stopped, and maintained by a single command,
   bind10. This command starts a master process which will start other
   processes as needed. The processes started by the bind10 command have
   names starting with "b10-", including:

     o b10-auth — Authoritative DNS server. This process serves DNS requests.
     o b10-cfgmgr — Configuration manager. This process maintains all of the
       configuration for BIND 10.
     o b10-cmdctl — Command and control service. This process allows external
       control of the BIND 10 system.
     o b10-ddns — Dynamic DNS update service. This process is used to handle
       incoming DNS update requests to allow granted clients to update zones
       for which BIND 10 is serving as a primary server.
     o b10-msgq — Message bus daemon. This process coordinates communication
       between all of the other BIND 10 processes.
     o b10-resolver — Recursive name server. This process handles incoming
       DNS queries and provides answers from its cache or by recursively
       doing remote lookups.
     o b10-sockcreator — Socket creator daemon. This process creates sockets
       used by network-listening BIND 10 processes.
     o b10-stats — Statistics collection daemon. This process collects and
       reports statistics data.
     o b10-stats-httpd — HTTP server for statistics reporting. This process
       reports statistics data in XML format over HTTP.
     o b10-xfrin — Incoming zone transfer service. This process is used to
       transfer a new copy of a zone into BIND 10, when acting as a secondary
       server.
     o b10-xfrout — Outgoing zone transfer service. This process is used to
       handle transfer requests to send a local zone to a remote secondary
       server.
     o b10-zonemgr — Secondary zone manager. This process keeps track of
       timers and other necessary information for BIND 10 to act as a slave
       server.

   These are ran by bind10 and do not need to be manually started
   independently.

1.4. Managing BIND 10

   Once BIND 10 is running, a few commands are used to interact directly with
   the system:

     o bindctl — Interactive administration interface. This is a low-level
       command-line tool which allows a developer or an experienced
       administrator to control BIND 10.
     o b10-loadzone — Zone file loader. This tool will load standard
       masterfile-format zone files into BIND 10.
     o b10-cmdctl-usermgr — User access control. This tool allows an
       administrator to authorize additional users to manage BIND 10.

   The tools and modules are covered in full detail in this guide. In
   addition, manual pages are also provided in the default installation.

   BIND 10 also provides libraries and programmer interfaces for C++ and
   Python for the message bus, configuration backend, and, of course, DNS.
   These include detailed developer documentation and code examples.

Chapter 2. Installation

   Table of Contents

   2.1. Packages

   2.2. Install Hierarchy

   2.3. Building Requirements

   2.4. Quick start

   2.5. Installation from source

                2.5.1. Download Tar File

                2.5.2. Retrieve from Git

                2.5.3. Configure before the build

                2.5.4. Build

                2.5.5. Install

2.1. Packages

   Some operating systems or softare package vendors may provide
   ready-to-use, pre-built software packages for the BIND 10 suite.
   Installing a pre-built package means you do not need to install build-only
   prerequisites and do not need to make the software.

   FreeBSD ports, NetBSD pkgsrc, and Debian testing package collections
   provide all the prerequisite packages.

2.2. Install Hierarchy

   The following is the standard, common layout of the complete BIND 10
   installation:

     o bin/ — general tools and diagnostic clients.
     o etc/bind10-devel/ — configuration files.
     o lib/ — libraries and python modules.
     o libexec/bind10-devel/ — executables that a user wouldn't normally run
       directly and are not run independently. These are the BIND 10 modules
       which are daemons started by the bind10 tool.
     o sbin/ — commands used by the system administrator.
     o share/bind10-devel/ — configuration specifications.
     o share/doc/bind10-devel/ — this guide and other supplementary
       documentation.
     o share/man/ — manual pages (online documentation).
     o var/bind10-devel/ — data source and configuration databases.

2.3. Building Requirements

   In addition to the run-time requirements (listed in Section 1.2, “Required
   Software at Run-time”), building BIND 10 from source code requires various
   development include headers and program development tools.

  Note

   Some operating systems have split their distribution packages into a
   run-time and a development package. You will need to install the
   development package versions, which include header files and libraries, to
   build BIND 10 from source code.

   Building from source code requires the Boost build-time headers
   (http://www.boost.org/). At least Boost version 1.35 is required.

   To build BIND 10, also install the Botan (at least version 1.8) and the
   log4cplus (at least version 1.0.3) development include headers.

   Building BIND 10 also requires a C++ compiler and standard development
   headers, make, and pkg-config. BIND 10 builds have been tested with GCC
   g++ 3.4.3, 4.1.2, 4.1.3, 4.2.1, 4.3.2, and 4.4.1; Clang++ 2.8; and Sun C++
   5.10.

   Visit the user-contributed wiki at
   http://bind10.isc.org/wiki/SystemSpecificNotes for system-specific
   installation tips.

2.4. Quick start

  Note

   This quickly covers the standard steps for installing and deploying BIND
   10 as an authoritative name server using its defaults. For
   troubleshooting, full customizations and further details, see the
   respective chapters in the BIND 10 guide.

   To quickly get started with BIND 10, follow these steps.

    1. Install required run-time and build dependencies.
    2. Download the BIND 10 source tar file from
       ftp://ftp.isc.org/isc/bind10/.
    3. Extract the tar file:

 $ gzcat bind10-VERSION.tar.gz | tar -xvf -

    4. Go into the source and run configure:

 $ cd bind10-VERSION
   $ ./configure

    5. Build it:

 $ make

    6. Install it (to default /usr/local):

 $ make install

    7. Start the server:

 $ /usr/local/sbin/bind10

    8. Test it; for example:

 $ dig @127.0.0.1 -c CH -t TXT authors.bind

    9. Load desired zone file(s), for example:

 $ b10-loadzone your.zone.example.org

   10. Test the new zone.

2.5. Installation from source

   BIND 10 is open source software written in C++ and Python. It is freely
   available in source code form from ISC as a downloadable tar file or via
   BIND 10's Git code revision control service. (It may also be available in
   pre-compiled ready-to-use packages from operating system vendors.)

  2.5.1. Download Tar File

   Downloading a release tar file is the recommended method to obtain the
   source code.

   The BIND 10 releases are available as tar file downloads from
   ftp://ftp.isc.org/isc/bind10/. Periodic development snapshots may also be
   available.

  2.5.2. Retrieve from Git

   Downloading this "bleeding edge" code is recommended only for developers
   or advanced users. Using development code in a production environment is
   not recommended.

  Note

   When using source code retrieved via Git, additional software will be
   required: automake (v1.11 or newer), libtoolize, and autoconf (2.59 or
   newer). These may need to be installed.

   The latest development code (and temporary experiments and un-reviewed
   code) is available via the BIND 10 code revision control system. This is
   powered by Git and all the BIND 10 development is public. The leading
   development is done in the “master” branch.

   The code can be checked out from git://git.bind10.isc.org/bind10; for
   example:

 $ git clone git://git.bind10.isc.org/bind10

   When checking out the code from the code version control system, it
   doesn't include the generated configure script, Makefile.in files, nor
   their related build files. They can be created by running autoreconf with
   the --install switch. This will run autoconf, aclocal, libtoolize,
   autoheader, automake, and related commands.

  2.5.3. Configure before the build

   BIND 10 uses the GNU Build System to discover build environment details.
   To generate the makefiles using the defaults, simply run:

 $ ./configure

   Run ./configure with the --help switch to view the different options. Some
   commonly-used options are:

   --prefix
           Define the installation location (the default is /usr/local/).

   --with-boost-include
           Define the path to find the Boost headers.

   --with-pythonpath
           Define the path to Python 3.1 if it is not in the standard
           execution path.

   --with-gtest
           Enable building the C++ Unit Tests using the Google Tests
           framework. Optionally this can define the path to the gtest header
           files and library.

   For example, the following configures it to find the Boost headers, find
   the Python interpreter, and sets the installation location:

 $ ./configure \
       --with-boost-include=/usr/pkg/include \
       --with-pythonpath=/usr/pkg/bin/python3.1 \
       --prefix=/opt/bind10

   If the configure fails, it may be due to missing or old dependencies.

  2.5.4. Build

   After the configure step is complete, to build the executables from the
   C++ code and prepare the Python scripts, run:

 $ make

  2.5.5. Install

   To install the BIND 10 executables, support files, and documentation, run:

 $ make install

  Note

   The install step may require superuser privileges.

Chapter 3. Starting BIND10 with bind10

   Table of Contents

   3.1. Starting BIND 10

   3.2. Configuration to start processes

   BIND 10 provides the bind10 command which starts up the required
   processes. bind10 will also restart some processes that exit unexpectedly.
   This is the only command needed to start the BIND 10 system.

   After starting the b10-msgq communications channel, bind10 connects to it,
   runs the configuration manager, and reads its own configuration. Then it
   starts the other modules.

   The b10-sockcreator, b10-msgq and b10-cfgmgr services make up the core.
   The b10-msgq daemon provides the communication channel between every part
   of the system. The b10-cfgmgr daemon is always needed by every module, if
   only to send information about themselves somewhere, but more importantly
   to ask about their own settings, and about other modules. The
   b10-sockcreator daemon helps allocate Internet addresses and ports as
   needed for BIND 10 network services.

   In its default configuration, the bind10 master process will also start up
   b10-cmdctl for administration tools to communicate with the system, and
   b10-stats for statistics collection.

3.1. Starting BIND 10

   To start the BIND 10 service, simply run bind10. Run it with the --verbose
   switch to get additional debugging or diagnostic output.

  Note

   If the setproctitle Python module is detected at start up, the process
   names for the Python-based daemons will be renamed to better identify them
   instead of just “python”. This is not needed on some operating systems.

3.2. Configuration to start processes

   The processes to be used can be configured for bind10 to start, with the
   exception of the required b10-sockcreator, b10-msgq and b10-cfgmgr
   components. The configuration is in the Boss/components section. Each
   element represents one component, which is an abstraction of a process.

   To add a process to the set, let's say the resolver (which is not started
   by default), you would do this:

 > config add Boss/components b10-resolver
 > config set Boss/components/b10-resolver/special resolver
 > config set Boss/components/b10-resolver/kind needed
 > config set Boss/components/b10-resolver/priority 10
 > config commit

   Now, what it means. We add an entry called “b10-resolver”. It is both a
   name used to reference this component in the configuration and the name of
   the process to start. Then we set some parameters on how to start it.

   The special setting is for components that need some kind of special care
   during startup or shutdown. Unless specified, the component is started in
   a usual way. This is the list of components that need to be started in a
   special way, with the value of special used for them:

   Table 3.1. Special startup components

   +----------------------------------------------------------------------+
   | Component    | Special  | Description                                |
   |--------------+----------+--------------------------------------------|
   | b10-auth     | auth     | Authoritative DNS server                   |
   |--------------+----------+--------------------------------------------|
   | b10-resolver | resolver | DNS resolver                               |
   |--------------+----------+--------------------------------------------|
   | b10-cmdctl   | cmdctl   | Command control (remote control interface) |
   +----------------------------------------------------------------------+

   The kind specifies how a failure of the component should be handled. If it
   is set to “dispensable” (the default unless you set something else), it
   will get started again if it fails. If it is set to “needed” and it fails
   at startup, the whole bind10 shuts down and exits with an error exit code.
   But if it fails some time later, it is just started again. If you set it
   to “core”, you indicate that the system is not usable without the
   component and if such component fails, the system shuts down no matter
   when the failure happened. This is the behaviour of the core components
   (the ones you can't turn off), but you can declare any other components as
   core as well if you wish (but you can turn these off, they just can't
   fail).

   The priority defines order in which the components should start. The ones
   with higher numbers are started sooner than the ones with lower ones. If
   you don't set it, 0 (zero) is used as the priority. Usually, leaving it at
   the default is enough.

   There are other parameters we didn't use in our example. One of them is
   address. It is the address used by the component on the b10-msgq message
   bus. The special components already know their address, but the usual ones
   don't. The address is by convention the thing after b10-, with the first
   letter capitalized (eg. b10-stats would have “Stats” as its address).

   The last one is process. It is the name of the process to be started. It
   defaults to the name of the component if not set, but you can use this to
   override it. (The special components also already know their executable
   name.)

  Note

   The configuration is quite powerful, but that includes a lot of space for
   mistakes. You could turn off the b10-cmdctl, but then you couldn't change
   it back the usual way, as it would require it to be running (you would
   have to find and edit the configuration directly). Also, some modules
   might have dependencies: b10-stats-httpd needs b10-stats, b10-xfrout needs
   b10-auth to be running, etc.

   In short, you should think twice before disabling something here.

   It is possible to start some components multiple times (currently b10-auth
   and b10-resolver). You might want to do that to gain more performance
   (each one uses only single core). Just put multiple entries under
   different names, like this, with the same config:

 > config add Boss/components b10-resolver-2
 > config set Boss/components/b10-resolver-2/special resolver
 > config set Boss/components/b10-resolver-2/kind needed
 > config commit

   However, this is work in progress and the support is not yet complete. For
   example, each resolver will have its own cache, each authoritative server
   will keep its own copy of in-memory data and there could be problems with
   locking the sqlite database, if used. The configuration might be changed
   to something more convenient in future. Other components don't expect such
   a situation, so it would probably not do what you want. Such support is
   yet to be implemented.

Chapter 4. Command channel

   The BIND 10 components use the b10-msgq message routing daemon to
   communicate with other BIND 10 components. The b10-msgq implements what is
   called the “Command Channel”. Processes intercommunicate by sending
   messages on the command channel. Example messages include shutdown, get
   configurations, and set configurations. This Command Channel is not used
   for DNS message passing. It is used only to control and monitor the BIND
   10 system.

   Administrators do not communicate directly with the b10-msgq daemon. By
   default, BIND 10 uses a UNIX domain socket file named
   /usr/local/var/bind10-devel/msg_socket for this interprocess
   communication.

Chapter 5. Configuration manager

   The configuration manager, b10-cfgmgr, handles all BIND 10 system
   configuration. It provides persistent storage for configuration, and
   notifies running modules of configuration changes.

   The b10-auth and b10-xfrin daemons and other components receive their
   configurations from the configuration manager over the b10-msgq command
   channel.

   The administrator doesn't connect to it directly, but uses a user
   interface to communicate with the configuration manager via b10-cmdctl's
   REST-ful interface. b10-cmdctl is covered in Chapter 6, Remote control
   daemon.

  Note

   The development prototype release only provides bindctl as a user
   interface to b10-cmdctl. Upcoming releases will provide another
   interactive command-line interface and a web-based interface.

   The b10-cfgmgr daemon can send all specifications and all current settings
   to the bindctl client (via b10-cmdctl). b10-cfgmgr relays configurations
   received from b10-cmdctl to the appropriate modules.

   The stored configuration file is at
   /usr/local/var/bind10-devel/b10-config.db. (The directory is what was
   defined at build configure time for --localstatedir. The default is
   /usr/local/var/.) The format is loosely based on JSON and is directly
   parseable python, but this may change in a future version. This
   configuration data file is not manually edited by the administrator.

   The configuration manager does not have any command line arguments.
   Normally it is not started manually, but is automatically started using
   the bind10 master process (as covered in Chapter 3, Starting BIND10 with
   bind10).

Chapter 6. Remote control daemon

   Table of Contents

   6.1. Configuration specification for b10-cmdctl

   b10-cmdctl is the gateway between administrators and the BIND 10 system.
   It is a HTTPS server that uses standard HTTP Digest Authentication for
   username and password validation. It provides a REST-ful interface for
   accessing and controlling BIND 10.

   When b10-cmdctl starts, it firsts asks b10-cfgmgr about what modules are
   running and what their configuration is (over the b10-msgq channel). Then
   it will start listening on HTTPS for clients — the user interface — such
   as bindctl.

   b10-cmdctl directly sends commands (received from the user interface) to
   the specified component. Configuration changes are actually commands to
   b10-cfgmgr so are sent there.

   The HTTPS server requires a private key, such as a RSA PRIVATE KEY. The
   default location is at /usr/local/etc/bind10-devel/cmdctl-keyfile.pem. (A
   sample key is at /usr/local/share/bind10-devel/cmdctl-keyfile.pem.) It
   also uses a certificate located at
   /usr/local/etc/bind10-devel/cmdctl-certfile.pem. (A sample certificate is
   at /usr/local/share/bind10-devel/cmdctl-certfile.pem.) This may be a
   self-signed certificate or purchased from a certification authority.

  Note

   The HTTPS server doesn't support a certificate request from a client (at
   this time). The b10-cmdctl daemon does not provide a public service. If
   any client wants to control BIND 10, then a certificate needs to be first
   received from the BIND 10 administrator. The BIND 10 installation provides
   a sample PEM bundle that matches the sample key and certificate.

   The b10-cmdctl daemon also requires the user account file located at
   /usr/local/etc/bind10-devel/cmdctl-accounts.csv. This comma-delimited file
   lists the accounts with a user name, hashed password, and salt. (A sample
   file is at /usr/local/share/bind10-devel/cmdctl-accounts.csv. It contains
   the user named “root” with the password “bind10”.)

   The administrator may create a user account with the b10-cmdctl-usermgr
   tool.

   By default the HTTPS server listens on the localhost port 8080. The port
   can be set by using the --port command line option. The address to listen
   on can be set using the --address command line argument. Each HTTPS
   connection is stateless and times out in 1200 seconds by default. This can
   be redefined by using the --idle-timeout command line argument.

6.1. Configuration specification for b10-cmdctl

   The configuration items for b10-cmdctl are: accounts_file which defines
   the path to the user accounts database (the default is
   /usr/local/etc/bind10-devel/cmdctl-accounts.csv); cert_file which defines
   the path to the PEM certificate file (the default is
   /usr/local/etc/bind10-devel/cmdctl-certfile.pem); and key_file which
   defines the path to the PEM private key file (the default is
   /usr/local/etc/bind10-devel/cmdctl-keyfile.pem).

Chapter 7. Control and configure user interface

  Note

   For this development prototype release, bindctl is the only user
   interface. It is expected that upcoming releases will provide another
   interactive command-line interface and a web-based interface for
   controlling and configuring BIND 10.

   The bindctl tool provides an interactive prompt for configuring,
   controlling, and querying the BIND 10 components. It communicates directly
   with a REST-ful interface over HTTPS provided by b10-cmdctl. It doesn't
   communicate to any other components directly.

   Configuration changes are actually commands to b10-cfgmgr. So when bindctl
   sends a configuration, it is sent to b10-cmdctl (over a HTTPS connection);
   then b10-cmdctl sends the command (over a b10-msgq command channel) to
   b10-cfgmgr which then stores the details and relays (over a b10-msgq
   command channel) the configuration on to the specified module.

Chapter 8. Authoritative Server

   Table of Contents

   8.1. Server Configurations

   8.2. Data Source Backends

                8.2.1. Data source types

                8.2.2. Examples

   8.3. Loading Master Zones Files

   The b10-auth is the authoritative DNS server. It supports EDNS0, DNSSEC,
   IPv6, and SQLite3 and in-memory zone data backends. Normally it is started
   by the bind10 master process.

8.1. Server Configurations

   b10-auth is configured via the b10-cfgmgr configuration manager. The
   module name is “Auth”. The configuration data items are:

   database_file
           This is an optional string to define the path to find the SQLite3
           database file. Note: This may be a temporary setting because the
           DNS server can use various data source backends.

   datasources
           datasources configures data sources. The list items include: type
           to define the required data source type (such as “memory”); class
           to optionally select the class (it defaults to “IN”); and zones to
           define the file path name, the filetype (“sqlite3” to load from a
           SQLite3 database file or “text” to load from a master text file),
           and the origin (default domain). By default, this is empty.

  Note

           In this development version, currently this is only used for the
           memory data source. Only the IN class is supported at this time.
           By default, the memory data source is disabled. Also, currently
           the zone file must be canonical such as generated by
           named-compilezone -D, or must be an SQLite3 database.

   listen_on
           listen_on is a list of addresses and ports for b10-auth to listen
           on. The list items are the address string and port number. By
           default, b10-auth listens on port 53 on the IPv6 (::) and IPv4
           (0.0.0.0) wildcard addresses.

  Note

           The default configuration is currently not appropriate for a
           multi-homed host. In case you have multiple public IP addresses,
           it is possible the query UDP packet comes through one interface
           and the answer goes out through another. The answer will probably
           be dropped by the client, as it has a different source address
           than the one it sent the query to. The client would fallback on
           TCP after several attempts, which works well in this situation,
           but is clearly not ideal.

           There are plans to solve the problem such that the server handles
           it by itself. But until it is actually implemented, it is
           recommended to alter the configuration — remove the wildcard
           addresses and list all addresses explicitly. Then the server will
           answer on the same interface the request came on, preserving the
           correct address.

   statistics-interval
           statistics-interval is the timer interval in seconds for b10-auth
           to share its statistics information to b10-stats(8). Statistics
           updates can be disabled by setting this to 0. The default is 60.

   The configuration commands are:

   loadzone
           loadzone tells b10-auth to load or reload a zone file. The
           arguments include: class which optionally defines the class (it
           defaults to “IN”); origin is the domain name of the zone; and
           datasrc optionally defines the type of datasource (it defaults to
           “memory”).

  Note

           In this development version, currently this only supports the IN
           class and the memory data source.

   sendstats
           sendstats tells b10-auth to send its statistics data to
           b10-stats(8) immediately.

   shutdown
           Stop the authoritative DNS server. This has an optional pid
           argument to select the process ID to stop. (Note that the BIND 10
           boss process may restart this service if configured.)

8.2. Data Source Backends

   Bind 10 has the concept of data sources. A data source is a place where
   authoritative zone data reside and where they can be served from. This can
   be a master file, a database or something completely different.

   Once a query arrives, b10-auth goes through a configured list of data
   sources and finds the one containing a best matching zone. From the
   equally good ones, the first one is taken. This data source is then used
   to answer the query.

  Note

   In the development prototype release, b10-auth can serve data from a
   SQLite3 data source backend and from master files. Upcoming versions will
   be able to use multiple different data sources, such as MySQL and Berkeley
   DB.

   The configuration is located in data_sources/classes. Each item there
   represents one RR class and a list used to answer queries for that class.
   The default contains two classes. The CH class contains a static data
   source — one that serves things like “AUTHORS.BIND.”. The IN class
   contains single SQLite3 data source with database file located at
   /usr/local/var/bind10-devel/zone.sqlite3.

   Each data source has several options. The first one is type, which
   specifies the type of data source to use. Valid types include the ones
   listed below, but bind10 uses dynamically loaded modules for them, so
   there may be more in your case. This option is mandatory.

   Another option is params. This option is type specific; it holds different
   data depending on the type above. Also, depending on the type, it could be
   possible to omit it.

   There are two options related to the so-called cache. If you enable cache,
   zone data from the data source are loaded into memory. Then, when
   answering a query, b10-auth looks into the memory only instead of the data
   source, which speeds answering up. The first option is cache-enable, a
   boolean value turning the cache on and off (off is the default). The
   second one, cache-zones, is a list of zone origins to load into in-memory.
   Remember that zones in the data source not listed here will not be loaded
   and will not be available at all.

  8.2.1. Data source types

   As mentioned, the type used by default is “sqlite3”. It has single
   configuration option inside params — database_file, which contains the
   path to the sqlite3 file containing the data.

   Another type is called “MasterFiles”. This one is slightly special. The
   data are stored in RFC1034 master files. Because answering directly from
   them would be impractical, this type mandates the cache to be enabled.
   Also, the list of zones (cache-zones) should be omitted. The params is a
   dictionary mapping from zone origins to the files they reside in.

  8.2.2. Examples

   As this is one of the more complex configurations of Bind10, we show some
   examples. They all assume they start with default configuration.

   First, let's disable the static data source (“VERSION.BIND” and friends).
   As it is the only data source in the CH class, we can remove the whole
   class.

 > config remove data_sources/classes CH
 > config commit

   Another one, let's say our default data source contains zones
   “example.org.” and “example.net.”. We want them to be served from memory
   to make the answering faster.

 > config set data_sources/classes/IN[0]/cache-enable true
 > config add data_sources/classes/IN[0]/cache-zones example.org.
 > config add data_sources/classes/IN[0]/cache-zones example.net.
 > config commit

   Now every time the zone in the data source is changed by the operator,
   Bind10 needs to be told to reload it, by

 > Auth loadzone example.org

   You don't need to do this when the zone is modified by XfrIn, it does so
   automatically.

   Now, the last example is when there are master files we want to serve in
   addition to whatever is inside the sqlite3 database.

 > config add data_sources/classes/IN
 > config set data_sources/classes/IN[1]/type MasterFiles
 > config set data_sources/classes/IN[1]/cache-enable true
 > config set data_sources/classes/IN[1]/params { "example.org": "/path/to/example.org", "example.com": "/path/to/example.com" }
 > config commit

   Initially, a map value has to be set, but this value may be an empty map.
   After that, key/value pairs can be added with 'config add' and keys can be
   removed with 'config remove'. The initial value may be an empty map, but
   it has to be set before zones are added or removed.

 > config set data_sources/classes/IN[1]/params {}
 > config add data_sources/classes/IN[1]/params another.example.org /path/to/another.example.org
 > config add data_sources/classes/IN[1]/params another.example.com /path/to/another.example.com
 > config remove data_sources/classes/IN[1]/params another.example.org


   bindctl. To reload a zone, you the same command as above.

  Note

   There's also Auth/database_file configuration variable, pointing to a
   sqlite3 database file. This is no longer used by b10-auth, but it is left
   in place for now, since other modules use it. Once b10-xfrin, b10-xfrout
   and b10-ddns are ported to the new configuration, this will disappear. But
   for now, make sure that if you use any of these modules, the new and old
   configuration correspond. The defaults are consistent, so unless you
   tweaked either the new or the old configuration, you're good.

8.3. Loading Master Zones Files

   RFC 1035 style DNS master zone files may imported into a BIND 10 SQLite3
   data source by using the b10-loadzone utility.

   b10-loadzone supports the following special directives (control entries):

   $INCLUDE
           Loads an additional zone file. This may be recursive.

   $ORIGIN
           Defines the relative domain name.

   $TTL
           Defines the time-to-live value used for following records that
           don't include a TTL.

   The -o argument may be used to define the default origin for loaded zone
   file records.

  Note

   In the development prototype release, only the SQLite3 back end is used by
   b10-loadzone. By default, it stores the zone data in
   /usr/local/var/bind10-devel/zone.sqlite3 unless the -d switch is used to
   set the database filename. Multiple zones are stored in a single SQLite3
   zone database.

   If you reload a zone already existing in the database, all records from
   that prior zone disappear and a whole new set appears.

Chapter 9. Incoming Zone Transfers

   Table of Contents

   9.1. Configuration for Incoming Zone Transfers

   9.2. Enabling IXFR

   9.3. Secondary Manager

   9.4. Trigger an Incoming Zone Transfer Manually

   9.5. Incoming Transfers with In-memory Datasource

   Incoming zones are transferred using the b10-xfrin process which is
   started by bind10. When received, the zone is stored in the corresponding
   BIND 10 data source, and its records can be served by b10-auth. In
   combination with b10-zonemgr (for automated SOA checks), this allows the
   BIND 10 server to provide secondary service.

   The b10-xfrin process supports both AXFR and IXFR. Due to some
   implementation limitations of the current development release, however, it
   only tries AXFR by default, and care should be taken to enable IXFR.

9.1. Configuration for Incoming Zone Transfers

   In practice, you need to specify a list of secondary zones to enable
   incoming zone transfers for these zones (you can still trigger a zone
   transfer manually, without a prior configuration (see below)).

   For example, to enable zone transfers for a zone named "example.com"
   (whose master address is assumed to be 2001:db8::53 here), run the
   following at the bindctl prompt:

 > config add Xfrin/zones
 > config set Xfrin/zones[0]/name "example.com"
 > config set Xfrin/zones[0]/master_addr "2001:db8::53"
 > config commit

   (We assume there has been no zone configuration before).

9.2. Enabling IXFR

   As noted above, b10-xfrin uses AXFR for zone transfers by default. To
   enable IXFR for zone transfers for a particular zone, set the use_ixfr
   configuration parameter to true. In the above example of configuration
   sequence, you'll need to add the following before performing commit:

 > config set Xfrin/zones[0]/use_ixfr true

  Note

   One reason why IXFR is disabled by default in the current release is
   because it does not support automatic fallback from IXFR to AXFR when it
   encounters a primary server that doesn't support outbound IXFR (and, not
   many existing implementations support it). Another, related reason is that
   it does not use AXFR even if it has no knowledge about the zone (like at
   the very first time the secondary server is set up). IXFR requires the
   "current version" of the zone, so obviously it doesn't work in this
   situation and AXFR is the only workable choice. The current release of
   b10-xfrin does not make this selection automatically. These features will
   be implemented in a near future version, at which point we will enable
   IXFR by default.

9.3. Secondary Manager

   The b10-zonemgr process is started by bind10. It keeps track of SOA
   refresh, retry, and expire timers and other details for BIND 10 to perform
   as a slave. When the b10-auth authoritative DNS server receives a NOTIFY
   message, b10-zonemgr may tell b10-xfrin to do a refresh to start an
   inbound zone transfer. The secondary manager resets its counters when a
   new zone is transferred in.

  Note

   Access control (such as allowing notifies) is not yet provided. The
   primary/secondary service is not yet complete.

   The following example shows using bindctl to configure the server to be a
   secondary for the example zone:

 > config add Zonemgr/secondary_zones
 > config set Zonemgr/secondary_zones[0]/name "example.com"
 > config commit

   If the zone does not exist in the data source already (i.e. no SOA record
   for it), b10-zonemgr will automatically tell b10-xfrin to transfer the
   zone in.

9.4. Trigger an Incoming Zone Transfer Manually

   To manually trigger a zone transfer to retrieve a remote zone, you may use
   the bindctl utility. For example, at the bindctl prompt run:

 > Xfrin retransfer zone_name="foo.example.org" master=192.0.2.99

9.5. Incoming Transfers with In-memory Datasource

   In the case of an incoming zone transfer, the received zone is first
   stored in the corresponding BIND 10 datasource. In case the secondary zone
   is served by an in-memory datasource with an SQLite3 backend, b10-auth is
   automatically sent a loadzone command to reload the corresponding zone
   into memory from the backend.

   The administrator doesn't have to do anything for b10-auth to serve the
   new version of the zone, except for the configuration such as the one
   described in Section 8.2, “Data Source Backends”.

Chapter 10. Outbound Zone Transfers

   The b10-xfrout process is started by bind10. When the b10-auth
   authoritative DNS server receives an AXFR or IXFR request, b10-auth
   internally forwards the request to b10-xfrout, which handles the rest of
   this request processing. This is used to provide primary DNS service to
   share zones to secondary name servers. The b10-xfrout is also used to send
   NOTIFY messages to secondary servers.

   A global or per zone transfer_acl configuration can be used to control
   accessibility of the outbound zone transfer service. By default,
   b10-xfrout allows any clients to perform zone transfers for any zones:

 > config show Xfrout/transfer_acl
 Xfrout/transfer_acl[0]  {"action": "ACCEPT"}    any     (default)

   You can change this to, for example, rejecting all transfer requests by
   default while allowing requests for the transfer of zone "example.com"
   from 192.0.2.1 and 2001:db8::1 as follows:

 > config set Xfrout/transfer_acl[0] {"action": "REJECT"}
 > config add Xfrout/zone_config
 > config set Xfrout/zone_config[0]/origin "example.com"
 > config set Xfrout/zone_config[0]/transfer_acl [{"action": "ACCEPT", "from": "192.0.2.1"},
                                                  {"action": "ACCEPT", "from": "2001:db8::1"}]
 > config commit

  Note

   In the above example the lines for transfer_acl were divided for
   readability. In the actual input it must be in a single line.

   If you want to require TSIG in access control, a system wide TSIG "key
   ring" must be configured. For example, to change the previous example to
   allowing requests from 192.0.2.1 signed by a TSIG with a key name of
   "key.example", you'll need to do this:

 > config set tsig_keys/keys ["key.example:<base64-key>"]
 > config set Xfrout/zone_config[0]/transfer_acl [{"action": "ACCEPT", "from": "192.0.2.1", "key": "key.example"}]
 > config commit

   Both b10-xfrout and b10-auth will use the system wide keyring to check
   TSIGs in the incoming messages and to sign responses.

  Note

   The way to specify zone specific configuration (ACLs, etc) is likely to be
   changed.

Chapter 11. Dynamic DNS Update

   Table of Contents

   11.1. Enabling Dynamic Update

   11.2. Access Control

   11.3. Miscellaneous Operational Issues

   BIND 10 supports the server side of the Dynamic DNS Update (DDNS) protocol
   as defined in RFC 2136. This service is provided by the b10-ddns
   component, which is started by the bind10 process if configured so.

   When the b10-auth authoritative DNS server receives an UPDATE request, it
   internally forwards the request to b10-ddns, which handles the rest of
   this request processing. When the processing is completed, b10-ddns will
   send a response to the client as specified in RFC 2136 (NOERROR for
   successful update, REFUSED if rejected due to ACL check, etc). If the zone
   has been changed as a result, it will internally notify b10-xfrout so that
   other secondary servers will be notified via the DNS NOTIFY protocol. In
   addition, if b10-auth serves the updated zone (as described in
   Section 8.2, “Data Source Backends”), b10-ddns will also notify b10-auth
   so that b10-auth will re-cache the updated zone content if necessary.

   The b10-ddns component supports requests over both UDP and TCP, and both
   IPv6 and IPv4; for TCP requests, however, it terminates the TCP connection
   immediately after each single request has been processed. Clients cannot
   reuse the same TCP connection for multiple requests. (This is a current
   implementation limitation of b10-ddns. While RFC 2136 doesn't specify
   anything about such reuse of TCP connection, there is no reason for
   disallowing it as RFC 1035 generally allows multiple requests sent over a
   single TCP connection. BIND 9 supports such reuse.)

   As of this writing b10-ddns does not support update forwarding for
   secondary zones. If it receives an update request for a secondary zone, it
   will immediately return a “not implemented” response.

  Note

   For feature completeness, update forwarding should be eventually
   supported. But currently it's considered a lower priority task and there
   is no specific plan of implementing this feature.

11.1. Enabling Dynamic Update

   First off, it must be made sure that a few components on which b10-ddns
   depends are configured to run, which are b10-auth and b10-zonemgr. In
   addition, b10-xfrout should also be configured to run; otherwise the
   notification after an update (see above) will fail with a timeout,
   suspending the DDNS service while b10-ddns waits for the response (see the
   description of the DDNS_UPDATE_NOTIFY_FAIL log message for further
   details). If BIND 10 is already configured to provide authoritative DNS
   service they should normally be configured to run already.

   Second, for the obvious reason dynamic update requires that the underlying
   data source storing the zone data be writable. In the current
   implementation this means the zone must be stored in an SQLite3-based data
   source. Also, in this development version, the b10-ddns component
   configures itself with the data source referring to the database_file
   configuration parameter of b10-auth. So this information must be
   configured correctly before starting b10-ddns.

  Note

   The way to configure data sources is now being revised. Configuration on
   the data source for DDNS will be very likely to be changed in a backward
   incompatible manner in a near future version.

   In general, if something goes wrong regarding the dependency described
   above, b10-ddns will log the related event at the warning or error level.
   It's advisable to check the log message when you first enable DDNS or if
   it doesn't work as you expect to see if there's any warning or error log
   message.

   Next, to enable the DDNS service, b10-ddns needs to be explicitly
   configured to run. It can be done by using the bindctl utility. For
   example:

 > config add Boss/components b10-ddns
 > config set Boss/components/b10-ddns/address DDNS
 > config set Boss/components/b10-ddns/kind dispensable
 > config commit

  Note

   In theory kind could be omitted because "dispensable" is its default. But
   there's some peculiar behavior (which should be a bug and should be fixed
   eventually; see Trac ticket #2064) with bindctl and you'll still need to
   specify that explicitly. Likewise, address may look unnecessary because
   b10-ddns would start and work without specifying it. But for it to
   shutdown gracefully this parameter should also be specified.

11.2. Access Control

   By default, b10-ddns rejects any update requests from any clients by
   returning a REFUSED response. To allow updates to take effect, an access
   control rule (called update ACL) with a policy allowing updates must
   explicitly be configured. Update ACL must be configured per zone basis in
   the zones configuration parameter of b10-ddns. This is a list of per-zone
   configurations regarding DDNS. Each list element consists of the following
   parameters:

   origin
           The zone's origin name

   class
           The RR class of the zone (normally “IN”, and in that case can be
           omitted in configuration)

   update_acl
           List of access control rules (ACL) for the zone

   The syntax of the ACL is the same as ACLs for other components. Specific
   examples are given below.

   In general, an update ACL rule that allows an update request should be
   configured with a TSIG key. This is an example update ACL that allows
   updates to the zone named “example.org” (of default RR class “IN”) from
   clients that send requests signed with a TSIG whose key name is
   "key.example.org" (and refuses all others):

 > config add DDNS/zones
 > config set DDNS/zones[0]/origin example.org
 > config add DDNS/zones[0]/update_acl {"action": "ACCEPT", "key": "key.example.org"}
 > config commit

   The TSIG key must be configured system wide (see Chapter 10, Outbound Zone
   Transfers.)

   Multiple rules can be specified in the ACL, and an ACL rule can consist of
   multiple constraints, such as a combination of IP address and TSIG. The
   following configuration sequence will add a new rule to the ACL created in
   the above example. This additional rule allows update requests sent from a
   client using TSIG key name of "key.example" (different from the key used
   in the previous example) and has an IPv6 address of ::1.

 > config add DDNS/zones[0]/update_acl {"action": "ACCEPT", "from": "::1", "key": "key.example"}
 > config show DDNS/zones[0]/update_acl
 DDNS/zones[0]/update_acl[0]     {"action": "ACCEPT", "key": "key.example.org"} any (modified)
 DDNS/zones[0]/update_acl[1]     {"action": "ACCEPT", "from": "::1", "key": "key.example"} any (modified)
 > config commit

   (Note the "add" in the first line. Before this sequence, we have had only
   entry in zones[0]/update_acl. The add command with a value (rule) adds a
   new entry and sets it to the given rule. Due to a limitation of the
   current implementation, it doesn't work if you first try to just add a new
   entry and then set it to a given rule.)

  Note

   The b10-ddns component accepts an ACL rule that just allows updates from a
   specific IP address (i.e., without requiring TSIG), but this is highly
   discouraged (remember that requests can be made over UDP and spoofing the
   source address of a UDP packet is often pretty easy). Unless you know what
   you are doing and that you can accept its consequence, any update ACL rule
   that allows updates should have a TSIG key in its constraints.

   The ACL rules will be checked in the listed order, and the first matching
   one will apply. If none of the rules matches, the default rule will apply,
   which is rejecting any requests in the case of b10-ddns.

   Other actions than "ACCEPT", namely "REJECT" and "DROP", can be used, too.
   See Chapter 12, Recursive Name Server about their effects.

   Currently update ACL can only control updates per zone basis; it's not
   possible to specify access control with higher granularity such as for
   particular domain names or specific types of RRs.

  Note

   Contrary to what RFC 2136 (literally) specifies, b10-ddns checks the
   update ACL before checking the prerequisites of the update request. This
   is a deliberate implementation decision. This counter intuitive
   specification has been repeatedly discussed among implementers and in the
   IETF, and it is now widely agreed that it does not make sense to strictly
   follow that part of RFC. One known specific bad result of following the
   RFC is that it could leak information about which name or record exists or
   does not exist in the zone as a result of prerequisite checks even if a
   zone is somehow configured to reject normal queries from arbitrary
   clients. There have been other troubles that could have been avoided if
   the ACL could be checked before the prerequisite check.

11.3. Miscellaneous Operational Issues

   Unlike BIND 9, BIND 10 currently does not support automatic re-signing of
   DNSSEC-signed zone when it's updated via DDNS. It could be possible to
   re-sign the updated zone afterwards or make sure the update request also
   updates related DNSSEC records, but that will be pretty error-prone
   operation. In general, it's not advisable to allow DDNS for a signed zone
   at this moment.

   Also unlike BIND 9, it's currently not possible to “freeze” a zone
   temporarily in order to suspend DDNS while you manually update the zone.
   If you need to make manual updates to a dynamic zone, you'll need to
   temporarily reject any updates to the zone via the update ACLs.

   Dynamic updates are only applicable to primary zones. In order to avoid
   updating secondary zones via DDNS requests, b10-ddns refers to the
   “secondary_zones” configuration of b10-zonemgr. Zones listed in
   “secondary_zones” will never be updated via DDNS regardless of the update
   ACL configuration; b10-ddns will return a NOTAUTH (server not
   authoritative for the zone) response. If you have a "conceptual" secondary
   zone whose content is a copy of some external source but is not updated
   via the standard zone transfers and therefore not listed in
   “secondary_zones”, be careful not to allow DDNS for the zone; it would be
   quite likely to lead to inconsistent state between different servers.
   Normally this should not be a problem because the default update ACL
   rejects any update requests, but you may want to take an extra care about
   the configuration if you have such type of secondary zones.

   The difference of two versions of a zone, before and after a DDNS
   transaction, is automatically recorded in the underlying data source, and
   can be retrieved in the form of outbound IXFR. This is done automatically;
   it does not require specific configuration to make this possible.

Chapter 12. Recursive Name Server

   Table of Contents

   12.1. Access Control

   12.2. Forwarding

   The b10-resolver process is started by bind10.

   The main bind10 process can be configured to select to run either the
   authoritative or resolver or both. By default, it doesn't start either
   one. You may change this using bindctl, for example:

 > config add Boss/components b10-resolver
 > config set Boss/components/b10-resolver/special resolver
 > config set Boss/components/b10-resolver/kind needed
 > config set Boss/components/b10-resolver/priority 10
 > config commit

   The master bind10 will stop and start the desired services.

   By default, the resolver listens on port 53 for 127.0.0.1 and ::1. The
   following example shows how it can be configured to listen on an
   additional address (and port):

 > config add Resolver/listen_on
 > config set Resolver/listen_on[2]/address "192.168.1.1"
 > config set Resolver/listen_on[2]/port 53
 > config commit

   (Replace the “2” as needed; run “config show Resolver/listen_on” if
   needed.)

12.1. Access Control

   By default, the b10-resolver daemon only accepts DNS queries from the
   localhost (127.0.0.1 and ::1). The Resolver/query_acl configuration may be
   used to reject, drop, or allow specific IPs or networks. This
   configuration list is first match.

   The configuration's action item may be set to “ACCEPT” to allow the
   incoming query, “REJECT” to respond with a DNS REFUSED return code, or
   “DROP” to ignore the query without any response (such as a blackhole). For
   more information, see the respective debugging messages:
   RESOLVER_QUERY_ACCEPTED, RESOLVER_QUERY_REJECTED, and
   RESOLVER_QUERY_DROPPED.

   The required configuration's from item is set to an IPv4 or IPv6 address,
   addresses with an network mask, or to the special lowercase keywords
   “any6” (for any IPv6 address) or “any4” (for any IPv4 address).

   For example to allow the 192.168.1.0/24 network to use your recursive name
   server, at the bindctl prompt run:

 > config add Resolver/query_acl
 > config set Resolver/query_acl[2]/action "ACCEPT"
 > config set Resolver/query_acl[2]/from "192.168.1.0/24"
 > config commit

   (Replace the “2” as needed; run “config show Resolver/query_acl” if
   needed.)

  Note

   This prototype access control configuration syntax may be changed.

12.2. Forwarding

   To enable forwarding, the upstream address and port must be configured to
   forward queries to, such as:

 > config set Resolver/forward_addresses [{ "address": "192.168.1.1", "port": 53 }]
 > config commit

   (Replace 192.168.1.1 to point to your full resolver.)

   Normal iterative name service can be re-enabled by clearing the forwarding
   address(es); for example:

 > config set Resolver/forward_addresses []
 > config commit

Chapter 13. DHCPv4 Server

   Table of Contents

   13.1. DHCPv4 Server Usage

   13.2. DHCPv4 Server Configuration

   13.3. Supported standards

   13.4. DHCPv4 Server Limitations

   Dynamic Host Configuration Protocol for IPv4 (DHCP or DHCPv4) and Dynamic
   Host Configuration Protocol for IPv6 (DHCPv6) are protocols that allow one
   node (server) to provision configuration parameters to many hosts and
   devices (clients). To ease deployment in larger networks, additional nodes
   (relays) may be deployed that facilitate communication between servers and
   clients. Even though principles of both DHCPv4 and DHCPv6 are somewhat
   similar, these are two radically different protocols. BIND10 offers server
   implementations for both DHCPv4 and DHCPv6. This chapter is about DHCP for
   IPv4. For a description of the DHCPv6 server, see Chapter 14, DHCPv6
   Server.

   The DHCPv4 server component is currently under intense development. You
   may want to check out BIND10 DHCP (Kea) wiki and recent posts on BIND10
   developers mailing list.

   The DHCPv4 and DHCPv6 components in BIND10 architecture are internally
   code named “Kea”.

  Note

   As of December 2011, both DHCPv4 and DHCPv6 components are skeleton
   servers. That means that while they are capable of performing DHCP
   configuration, they are not fully functional yet. In particular, neither
   has functional lease databases. This means that they will assign the same,
   fixed, hardcoded addresses to any client that will ask. See Section 13.4,
   “DHCPv4 Server Limitations” and Section 14.4, “DHCPv6 Server Limitations”
   for detailed description.

13.1. DHCPv4 Server Usage

   BIND10 provides the DHCPv4 server component since December 2011. It is a
   skeleton server and can be described as an early prototype that is not
   fully functional yet. It is mature enough to conduct first tests in lab
   environment, but it has significant limitations. See Section 13.4, “DHCPv4
   Server Limitations” for details.

   b10-dhcp4 is a BIND10 component and is being run under BIND10 framework.
   To add a DHCPv4 process to the set of running BIND10 services, you can use
   following commands in bindctl:

 > config add Boss/components b10-dhcp4
 > config set Boss/components/b10-dhcp4/kind dispensable
 > config commit

   To shutdown running b10-dhcp4, please use the following command:

 > Dhcp4 shutdown

   or

 > config remove Boss/components b10-dhcp4
 > config commit

   During start-up the server will detect available network interfaces and
   will attempt to open UDP sockets on all interfaces that are up, running,
   are not loopback, and have IPv4 address assigned. The server will then
   listen to incoming traffic. Currently supported client messages are
   DISCOVER and REQUEST. The server will respond to them with OFFER and ACK,
   respectively. Since the DHCPv4 server opens privileged ports, it requires
   root access. Make sure you run this daemon as root.

13.2. DHCPv4 Server Configuration

   The DHCPv4 server does not have a lease database implemented yet nor any
   support for configuration, so every time the same set of configuration
   options (including the same fixed address) will be assigned every time.

   At this stage of development, the only way to alter the server
   configuration is to tweak its source code. To do so, please edit
   src/bin/dhcp4/dhcp4_srv.cc file and modify following parameters and
   recompile:

 const std::string HARDCODED_LEASE = "192.0.2.222"; // assigned lease
 const std::string HARDCODED_NETMASK = "255.255.255.0";
 const uint32_t    HARDCODED_LEASE_TIME = 60; // in seconds
 const std::string HARDCODED_GATEWAY = "192.0.2.1";
 const std::string HARDCODED_DNS_SERVER = "192.0.2.2";
 const std::string HARDCODED_DOMAIN_NAME = "isc.example.com";
 const std::string HARDCODED_SERVER_ID = "192.0.2.1";

   Lease database and configuration support is planned for 2012.

13.3. Supported standards

   The following standards and draft standards are currently supported:

     o RFC2131: Supported messages are DISCOVER, OFFER, REQUEST, and ACK.
     o RFC2132: Supported options are: PAD (0), END(255), Message Type(53),
       DHCP Server Identifier (54), Domain Name (15), DNS Servers (6), IP
       Address Lease Time (51), Subnet mask (1), and Routers (3).

13.4. DHCPv4 Server Limitations

   These are the current limitations of the DHCPv4 server software. Most of
   them are reflections of the early stage of development and should be
   treated as “not implemented yet”, rather than actual limitations.

     o During initial IPv4 node configuration, the server is expected to send
       packets to a node that does not have IPv4 address assigned yet. The
       server requires certain tricks (or hacks) to transmit such packets.
       This is not implemented yet, therefore DHCPv4 server supports relayed
       traffic only (that is, normal point to point communication).
     o b10-dhcp4 provides a single, fixed, hardcoded lease to any client that
       asks. There is no lease manager implemented. If two clients request
       addresses, they will both get the same fixed address.
     o b10-dhcp4 does not support any configuration mechanisms yet. The whole
       configuration is currently hardcoded. The only way to tweak
       configuration is to directly modify source code. See see Section 13.2,
       “DHCPv4 Server Configuration” for details.
     o Upon start, the server will open sockets on all interfaces that are
       not loopback, are up and running and have IPv4 address.
     o PRL (Parameter Request List, a list of options requested by a client)
       is currently ignored and server assigns DNS SERVER and DOMAIN NAME
       options.
     o b10-dhcp4 does not support BOOTP. That is a design choice. This
       limitation is permanent. If you have legacy nodes that can't use DHCP
       and require BOOTP support, please use latest version of ISC DHCP
       http://www.isc.org/software/dhcp.
     o Interface detection is currently working on Linux only. See
       Section 15.1, “Interface detection” for details.
     o b10-dhcp4 does not verify that assigned address is unused. According
       to RFC2131, the allocating server should verify that address is no
       used by sending ICMP echo request.
     o Address renewal (RENEW), rebinding (REBIND), confirmation (CONFIRM),
       duplication report (DECLINE) and release (RELEASE) are not supported
       yet.
     o DNS Update is not supported yet.
     o -v (verbose) command line option is currently the default, and cannot
       be disabled.

Chapter 14. DHCPv6 Server

   Table of Contents

   14.1. DHCPv6 Server Usage

   14.2. DHCPv6 Server Configuration

   14.3. Supported DHCPv6 Standards

   14.4. DHCPv6 Server Limitations

   Dynamic Host Configuration Protocol for IPv6 (DHCPv6) is specified in
   RFC3315. BIND10 provides DHCPv6 server implementation that is described in
   this chapter. For a description of the DHCPv4 server implementation, see
   Chapter 13, DHCPv4 Server.

   The DHCPv6 server component is currently under intense development. You
   may want to check out BIND10 DHCP (Kea) wiki and recent posts on BIND10
   developers mailing list.

   The DHCPv4 and DHCPv6 components in BIND10 architecture are internally
   code named “Kea”.

  Note

   As of December 2011, both DHCPv4 and DHCPv6 components are skeleton
   servers. That means that while they are capable of performing DHCP
   configuration, they are not fully functional yet. In particular, neither
   has functional lease databases. This means that they will assign the same,
   fixed, hardcoded addresses to any client that will ask. See Section 13.4,
   “DHCPv4 Server Limitations” and Section 14.4, “DHCPv6 Server Limitations”
   for detailed description.

14.1. DHCPv6 Server Usage

   BIND10 provides the DHCPv6 server component since September 2011. It is a
   skeleton server and can be described as an early prototype that is not
   fully functional yet. It is mature enough to conduct first tests in lab
   environment, but it has significant limitations. See Section 14.4, “DHCPv6
   Server Limitations” for details.

   b10-dhcp6 is a BIND10 component and is being run under BIND10 framework.
   To add a DHCPv6 process to the set of running BIND10 services, you can use
   following commands in bindctl:

 > config add Boss/components b10-dhcp6
 > config set Boss/components/b10-dhcp6/kind dispensable
 > config commit

   To shutdown running b10-dhcp6, please use the following command:

 > Dhcp6 shutdown

   or

 > config remove Boss/components b10-dhcp6
 > config commit

   During start-up the server will detect available network interfaces and
   will attempt to open UDP sockets on all interfaces that are up, running,
   are not loopback, are multicast-capable, and have IPv6 address assigned.
   The server will then listen to incoming traffic. Currently supported
   client messages are SOLICIT and REQUEST. The server will respond to them
   with ADVERTISE and REPLY, respectively. Since the DHCPv6 server opens
   privileged ports, it requires root access. Make sure you run this daemon
   as root.

14.2. DHCPv6 Server Configuration

   The DHCPv6 server does not have lease database implemented yet or any
   support for configuration, so every time the same set of configuration
   options (including the same fixed address) will be assigned every time.

   At this stage of development, the only way to alter server configuration
   is to tweak its source code. To do so, please edit
   src/bin/dhcp6/dhcp6_srv.cc file, modify the following parameters and
   recompile:

 const std::string HARDCODED_LEASE = "2001:db8:1::1234:abcd";
 const uint32_t HARDCODED_T1 = 1500; // in seconds
 const uint32_t HARDCODED_T2 = 2600; // in seconds
 const uint32_t HARDCODED_PREFERRED_LIFETIME = 3600; // in seconds
 const uint32_t HARDCODED_VALID_LIFETIME = 7200; // in seconds
 const std::string HARDCODED_DNS_SERVER = "2001:db8:1::1";

   Lease database and configuration support is planned for 2012.

14.3. Supported DHCPv6 Standards

   The following standards and draft standards are currently supported:

     o RFC3315: Supported messages are SOLICIT, ADVERTISE, REQUEST, and
       REPLY. Supported options are SERVER_ID, CLIENT_ID, IA_NA, and
       IAADDRESS.
     o RFC3646: Supported option is DNS_SERVERS.

14.4. DHCPv6 Server Limitations

   These are the current limitations of the DHCPv6 server software. Most of
   them are reflections of the early stage of development and should be
   treated as “not implemented yet”, rather than actual limitations.

     o Relayed traffic is not supported.
     o b10-dhcp6 provides a single, fixed, hardcoded lease to any client that
       asks. There is no lease manager implemented. If two clients request
       addresses, they will both get the same fixed address.
     o b10-dhcp6 does not support any configuration mechanisms yet. The whole
       configuration is currently hardcoded. The only way to tweak
       configuration is to directly modify source code. See see Section 14.2,
       “DHCPv6 Server Configuration” for details.
     o Upon start, the server will open sockets on all interfaces that are
       not loopback, are up, running and are multicast capable and have IPv6
       address. Support for multiple interfaces is not coded in reception
       routines yet, so if you are running this code on a machine that has
       many interfaces and b10-dhcp6 happens to listen on wrong interface,
       the easiest way to work around this problem is to turn down other
       interfaces. This limitation will be fixed shortly.
     o ORO (Option Request Option, a list of options requested by a client)
       is currently ignored and server assigns DNS SERVER option.
     o Temporary addresses are not supported yet.
     o Prefix delegation is not supported yet.
     o Address renewal (RENEW), rebinding (REBIND), confirmation (CONFIRM),
       duplication report (DECLINE) and release (RELEASE) are not supported
       yet.
     o DNS Update is not supported yet.
     o Interface detection is currently working on Linux only. See
       Section 15.1, “Interface detection” for details.
     o -v (verbose) command line option is currently the default, and cannot
       be disabled.

Chapter 15. libdhcp++ library

   Table of Contents

   15.1. Interface detection

   15.2. DHCPv4/DHCPv6 packet handling

   libdhcp++ is a common library written in C++ that handles many
   DHCP-related tasks, like DHCPv4 and DHCPv6 packets parsing, manipulation
   and assembly, option parsing, manipulation and assembly, network interface
   detection and socket operations, like socket creations, data transmission
   and reception and socket closing.

   While this library is currently used by b10-dhcp4 and b10-dhcp6 only, it
   is designed to be portable, universal library useful for any kind of
   DHCP-related software.

15.1. Interface detection

   Both DHCPv4 and DHCPv6 components share network interface detection
   routines. Interface detection is currently only supported on Linux
   systems.

   For non-Linux systems, there is currently stub implementation provided.
   Interface manager detects loopback interfaces only as their name (lo or
   lo0) can be easily predicted. Please contact BIND10 development team if
   you are interested in running DHCP components on systems other than Linux.

15.2. DHCPv4/DHCPv6 packet handling

   TODO: Describe packet handling here, with pointers to wiki

Chapter 16. Statistics

   The b10-stats process is started by bind10. It periodically collects
   statistics data from various modules and aggregates it.

   This stats daemon provides commands to identify if it is running, show
   specified or all statistics data, and show specified or all statistics data
   schema. For example, using bindctl:

 > Stats show
 {
     "Auth": {
         "opcode.iquery": 0,
         "opcode.notify": 10,
         "opcode.query": 869617,
         ...
         "queries.tcp": 1749,
         "queries.udp": 867868
     },
     "Boss": {
         "boot_time": "2011-01-20T16:59:03Z"
     },
     "Stats": {
         "boot_time": "2011-01-20T16:59:05Z",
         "last_update_time": "2011-01-20T17:04:05Z",
         "lname": "4d3869d9_a@jreed.example.net",
         "report_time": "2011-01-20T17:04:06Z",
         "timestamp": 1295543046.823504
     }
 }


Chapter 17. Logging

   Table of Contents

   17.1. Logging configuration

                17.1.1. Loggers

                17.1.2. Output Options

                17.1.3. Example session

   17.2. Logging Message Format

17.1. Logging configuration

   The logging system in BIND 10 is configured through the Logging module.
   All BIND 10 modules will look at the configuration in Logging to see what
   should be logged and to where.

  17.1.1. Loggers

   Within BIND 10, a message is logged through a component called a "logger".
   Different parts of BIND 10 log messages through different loggers, and
   each logger can be configured independently of one another.

   In the Logging module, you can specify the configuration for zero or more
   loggers; any that are not specified will take appropriate default values.

   The three most important elements of a logger configuration are the name
   (the component that is generating the messages), the severity (what to
   log), and the output_options (where to log).

    17.1.1.1. name (string)

   Each logger in the system has a name, the name being that of the component
   using it to log messages. For instance, if you want to configure logging
   for the resolver module, you add an entry for a logger named “Resolver”.
   This configuration will then be used by the loggers in the Resolver
   module, and all the libraries used by it.

   If you want to specify logging for one specific library within the module,
   you set the name to module.library. For example, the logger used by the
   nameserver address store component has the full name of “Resolver.nsas”.
   If there is no entry in Logging for a particular library, it will use the
   configuration given for the module.

   To illustrate this, suppose you want the cache library to log messages of
   severity DEBUG, and the rest of the resolver code to log messages of
   severity INFO. To achieve this you specify two loggers, one with the name
   “Resolver” and severity INFO, and one with the name “Resolver.cache” with
   severity DEBUG. As there are no entries for other libraries (e.g. the
   nsas), they will use the configuration for the module (“Resolver”), so
   giving the desired behavior.

   One special case is that of a module name of “*” (asterisks), which is
   interpreted as any module. You can set global logging options by using
   this, including setting the logging configuration for a library that is
   used by multiple modules (e.g. “*.config” specifies the configuration
   library code in whatever module is using it).

   If there are multiple logger specifications in the configuration that
   might match a particular logger, the specification with the more specific
   logger name takes precedence. For example, if there are entries for for
   both “*” and “Resolver”, the resolver module — and all libraries it uses —
   will log messages according to the configuration in the second entry
   (“Resolver”). All other modules will use the configuration of the first
   entry (“*”). If there was also a configuration entry for “Resolver.cache”,
   the cache library within the resolver would use that in preference to the
   entry for “Resolver”.

   One final note about the naming. When specifying the module name within a
   logger, use the name of the module as specified in bindctl, e.g.
   “Resolver” for the resolver module, “Xfrout” for the xfrout module, etc.
   When the message is logged, the message will include the name of the
   logger generating the message, but with the module name replaced by the
   name of the process implementing the module (so for example, a message
   generated by the “Auth.cache” logger will appear in the output with a
   logger name of “b10-auth.cache”).

    17.1.1.2. severity (string)

   This specifies the category of messages logged. Each message is logged
   with an associated severity which may be one of the following (in
   descending order of severity):

     o FATAL
     o ERROR
     o WARN
     o INFO
     o DEBUG

   When the severity of a logger is set to one of these values, it will only
   log messages of that severity, and the severities above it. The severity
   may also be set to NONE, in which case all messages from that logger are
   inhibited.

    17.1.1.3. output_options (list)

   Each logger can have zero or more output_options. These specify where log
   messages are sent to. These are explained in detail below.

   The other options for a logger are:

    17.1.1.4. debuglevel (integer)

   When a logger's severity is set to DEBUG, this value specifies what debug
   messages should be printed. It ranges from 0 (least verbose) to 99 (most
   verbose).

   If severity for the logger is not DEBUG, this value is ignored.

    17.1.1.5. additive (true or false)

   If this is true, the output_options from the parent will be used. For
   example, if there are two loggers configured; “Resolver” and
   “Resolver.cache”, and additive is true in the second, it will write the
   log messages not only to the destinations specified for “Resolver.cache”,
   but also to the destinations as specified in the output_options in the
   logger named “Resolver”.

  17.1.2. Output Options

   The main settings for an output option are the destination and a value
   called output, the meaning of which depends on the destination that is
   set.

    17.1.2.1. destination (string)

   The destination is the type of output. It can be one of:

     o console
     o file
     o syslog

    17.1.2.2. output (string)

   Depending on what is set as the output destination, this value is
   interpreted as follows:

   destination is “console”

           The value of output must be one of “stdout” (messages printed to
           standard output) or “stderr” (messages printed to standard error).

           Note: if output is set to “stderr” and a lot of messages are
           produced in a short time (e.g. if the logging level is set to
           DEBUG), you may occasionally see some messages jumbled up
           together. This is due to a combination of the way that messages
           are written to the screen and the unbuffered nature of the
           standard error stream. If this occurs, it is recommended that
           output be set to “stdout”.

   destination is “file”

           The value of output is interpreted as a file name; log messages
           will be appended to this file.

   destination is “syslog”

           The value of output is interpreted as the syslog facility (e.g.
           local0) that should be used for log messages.

   The other options for output_options are:

      17.1.2.2.1. flush (true of false)

   Flush buffers after each log message. Doing this will reduce performance
   but will ensure that if the program terminates abnormally, all messages up
   to the point of termination are output.

      17.1.2.2.2. maxsize (integer)

   Only relevant when destination is file, this is maximum file size of
   output files in bytes. When the maximum size is reached, the file is
   renamed and a new file opened. (For example, a ".1" is appended to the
   name — if a ".1" file exists, it is renamed ".2", etc.)

   If this is 0, no maximum file size is used.

      17.1.2.2.3. maxver (integer)

   Maximum number of old log files to keep around when rolling the output
   file. Only relevant when destination is “file”.

  17.1.3. Example session

   In this example we want to set the global logging to write to the file
   /var/log/my_bind10.log, at severity WARN. We want the authoritative server
   to log at DEBUG with debuglevel 40, to a different file
   (/tmp/debug_messages).

   Start bindctl.

 ["login success "]
 > config show Logging
 Logging/loggers []      list

   By default, no specific loggers are configured, in which case the severity
   defaults to INFO and the output is written to stderr.

   Let's first add a default logger:

 > config add Logging/loggers
 > config show Logging
 Logging/loggers/        list    (modified)

   The loggers value line changed to indicate that it is no longer an empty
   list:

 > config show Logging/loggers
 Logging/loggers[0]/name ""      string  (default)
 Logging/loggers[0]/severity     "INFO"  string  (default)
 Logging/loggers[0]/debuglevel   0       integer (default)
 Logging/loggers[0]/additive     false   boolean (default)
 Logging/loggers[0]/output_options       []      list    (default)

   The name is mandatory, so we must set it. We will also change the severity
   as well. Let's start with the global logger.

 > config set Logging/loggers[0]/name *
 > config set Logging/loggers[0]/severity WARN
 > config show Logging/loggers
 Logging/loggers[0]/name "*"     string  (modified)
 Logging/loggers[0]/severity     "WARN"  string  (modified)
 Logging/loggers[0]/debuglevel   0       integer (default)
 Logging/loggers[0]/additive     false   boolean (default)
 Logging/loggers[0]/output_options       []      list    (default)

   Of course, we need to specify where we want the log messages to go, so we
   add an entry for an output option.

 >  config add Logging/loggers[0]/output_options
 >  config show Logging/loggers[0]/output_options
 Logging/loggers[0]/output_options[0]/destination        "console"       string  (default)
 Logging/loggers[0]/output_options[0]/output     "stdout"        string  (default)
 Logging/loggers[0]/output_options[0]/flush      false   boolean (default)
 Logging/loggers[0]/output_options[0]/maxsize    0       integer (default)
 Logging/loggers[0]/output_options[0]/maxver     0       integer (default)

   These aren't the values we are looking for.

 >  config set Logging/loggers[0]/output_options[0]/destination file
 >  config set Logging/loggers[0]/output_options[0]/output /var/log/bind10.log
 >  config set Logging/loggers[0]/output_options[0]/maxsize 204800
 >  config set Logging/loggers[0]/output_options[0]/maxver 8

   Which would make the entire configuration for this logger look like:

 >  config show all Logging/loggers
 Logging/loggers[0]/name "*"     string  (modified)
 Logging/loggers[0]/severity     "WARN"  string  (modified)
 Logging/loggers[0]/debuglevel   0       integer (default)
 Logging/loggers[0]/additive     false   boolean (default)
 Logging/loggers[0]/output_options[0]/destination        "file"  string  (modified)
 Logging/loggers[0]/output_options[0]/output     "/var/log/bind10.log"   string  (modified)
 Logging/loggers[0]/output_options[0]/flush      false   boolean (default)
 Logging/loggers[0]/output_options[0]/maxsize    204800  integer (modified)
 Logging/loggers[0]/output_options[0]/maxver     8       integer (modified)

   That looks OK, so let's commit it before we add the configuration for the
   authoritative server's logger.

 >  config commit

   Now that we have set it, and checked each value along the way, adding a
   second entry is quite similar.

 >  config add Logging/loggers
 >  config set Logging/loggers[1]/name Auth
 >  config set Logging/loggers[1]/severity DEBUG
 >  config set Logging/loggers[1]/debuglevel 40
 >  config add Logging/loggers[1]/output_options
 >  config set Logging/loggers[1]/output_options[0]/destination file
 >  config set Logging/loggers[1]/output_options[0]/output /tmp/auth_debug.log
 >  config commit

   And that's it. Once we have found whatever it was we needed the debug
   messages for, we can simply remove the second logger to let the
   authoritative server use the same settings as the rest.

 >  config remove Logging/loggers[1]
 >  config commit

   And every module will now be using the values from the logger named “*”.

17.2. Logging Message Format

   Each message written by BIND 10 to the configured logging destinations
   comprises a number of components that identify the origin of the message
   and, if the message indicates a problem, information about the problem
   that may be useful in fixing it.

   Consider the message below logged to a file:

 2011-06-15 13:48:22.034 ERROR [b10-resolver.asiolink]
     ASIODNS_OPENSOCK error 111 opening TCP socket to 127.0.0.1(53)

   Note: the layout of messages written to the system logging file (syslog)
   may be slightly different. This message has been split across two lines
   here for display reasons; in the logging file, it will appear on one
   line.)

   The log message comprises a number of components:

   2011-06-15 13:48:22.034

           The date and time at which the message was generated.

   ERROR

           The severity of the message.

   [b10-resolver.asiolink]

           The source of the message. This comprises two components: the BIND
           10 process generating the message (in this case, b10-resolver) and
           the module within the program from which the message originated
           (which in the example is the asynchronous I/O link module,
           asiolink).

   ASIODNS_OPENSOCK

           The message identification. Every message in BIND 10 has a unique
           identification, which can be used as an index into the BIND 10
           Messages Manual (http://bind10.isc.org/docs/bind10-messages.html)
           from which more information can be obtained.

   error 111 opening TCP socket to 127.0.0.1(53)

           A brief description of the cause of the problem. Within this text,
           information relating to the condition that caused the message to
           be logged will be included. In this example, error number 111 (an
           operating system-specific error number) was encountered when
           trying to open a TCP connection to port 53 on the local system
           (address 127.0.0.1). The next step would be to find out the reason
           for the failure by consulting your system's documentation to
           identify what error number 111 means.