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joind(8)
NAME
  joind - BOOTP and DHCP server daemon

SYNOPSIS
  /usr/sbin/joind [-f] [-dn] [-ln] [-t minutes]

OPTIONS
  -f  Sets foreground mode.  In this mode, joind will not run as a daemon.
      All messages are written to standard out (stdout) and standard error
      (stderr), although warnings and errors are still sent to syslog(3) as
      well.

  -dn Sets debug level to n.  If debug is turned on, log messages are also
      enabled.

  -ln Enables warning (n > 0) and log (n > 1) messages.	 If n is not
      explicitly given, the value one (1) is assumed (warnings are turned
      on).

  -t minutes
      Terminates if minutes have passed and no packets have been received.
      This option is valid only if joind was started from inetd.

DESCRIPTION
  The joind server is the server that provides configurations to clients on
  the network using the DHCP or BOOTP protocols; it normally runs as a daemon
  process, and may be started either from the shell command line interface or
  by the inetd daemon.

  In default mode of operation, joind reads configuration and policy
  information from files created by xjoin, the graphical user interface tool
  for administering these databases.  It then listens on a well-known port
  for client hosts requesting configuration either by the DHCP protocol or by
  the BOOTP protocol.

  The joind daemon looks in the /etc/services file to find the port numbers
  it should use.  Two entries are extracted:

  bootps
      The BOOTP server listening port.

  bootpc
      The destination port used to reply to clients.

  If the port numbers cannot be determined in this manner, they are assumed
  to be port 67 for the server and port 68 for the client.

  When a request is received from a client on a network that is administered
  by a joind daemon, it responds with an Internet address that the client can
  use, and sufficient information to permit the client to boot and configure
  its TCP/IP stack according to either the DHCP or BOOTP protocols as
  described in RFC1541 and RFC1497, respectively.

  The joind daemon rereads its configuration file when it receives a hangup
  signal (SIGHUP) or when it receives a BOOTP request packet and detects that
  the file has been updated.  Hosts can be added, deleted, or modified when
  the configuration file is reread.

  The joind server writes informational and error messages in four
  categories: errors, warnings, information, and debug. Errors are severe,
  usually unrecoverable events within the server due to resource exhaustion
  and other unexpected failure of system calls. Warnings are less severe, do
  not terminate the server, and in most cases describe unusual or incorrect
  datagrams received from clients, or requests for service that cannot be
  provided.  Informational messages provide a human readable transcription of
  (correct) actions performed by the server on behalf of client hosts. Debug
  messages may be generated at various levels of verbosity from zero (not at
  all) through nine, as controlled by the -d option.

  The disposition of messages is (by default) as follows: warning,
  information, and debug messages are discarded: errors are written to
  /var/join/log and are sent to the system logger syslog(3) at priority
  LOG_ERR and with a facility identifier LOG_DAEMON. If warnings were
  enabled, they are also sent to syslog with the same facility, but at
  priority LOG_WARNING. The creation and disposition of messages is
  controlled by the -f, -d, and -l command line options, and the environment
  variable JOINLOG.

  BOOTP Information

  If you plan to use the joind daemon to support BOOTP requests only, you
  might want the inetd daemon start joind automatically.  To do this,
  uncomment the following line in the /etc/inetd.conf file:

       bootps dgram udp wait root /usr/sbin/joind joind

  This causes joind to be started only when a boot request arrives.  If joind
  does not receive another boot request within fifteen minutes of the last
  one it received, it exits to conserve system resources.

  To run the joind daemon, you must also run the tftpd daemon.

  Upon startup, joind first reads its configuration file, /etc/bootptab, and
  then begins listening for BOOTREQUEST packets.

RESTRICTIONS
  A cluster member should never be a DHCP client. It should always use static
  addressing.

  If a cluster is to support a DHCP server, there can be only one DHCP server
  for all the cluster members using a common database with failover.

  Do not terminate the server with SIGKILL. Doing so leads to data loss, and
  frequently results in a corrupted database. Use SIGTERM, SIGINT or SIGQUIT
  instead.

  Nonstandard subnet masks for all networks administered by the server must
  be available either through /etc/join/netmasks or NIS.

  The database used by the server does not support multiuser write
  concurrency.	When the server is in operation the entire database is locked
  against other applications.  This means that you cannot use jdbmod or
  xjdbmod to modify records in the database while the server is running.  The
  converse is also true.

  If the naming policy is to be changed (for example, from assigning names by
  MAC address to assigning names by IP address) you must first, before
  changing the server policy database, stop the server, dump the name data
  (using jdbdump), and then reload after the policy file has changed.

SIGNALS
  SIGTERM, SIGINT, SIGQUIT and SIGUSR2 terminate the server in a controlled
  manner.  SIGHUP tells the server to reread its configuration databases.
  SIGUSR1 dumps database internals.

  Never stop the server with SIGKILL. This leads to data loss and corruption
  of the lease and names databases.

FILES
  By default, joind reads its configuration and policy databases from files
  in the /etc/join directory.  The environment variable JOINCONFIG may be
  used to select a different directory. These databases may be stored as text
  or binary.  The text files are:

  /etc/bootptab
      Parameters and configuration data for individual clients, client
      classes, and networks.

  nets
      Networks joind controls, and a pool of IP addresses which are available
      for the server to assign to clients.

  namepool
      A collection of names available on a per-join-server, per domain-name
      that the server can assign to clients.

  server.pcy
      Parameters governing the behavior of joind, and general policies
      concerning network administration and their binary counterparts:
      bootptab.hsh, nets.hsh, namepool.hsh, and server.hsh.

  During operation, the server creates dynamic database bindings of IP
  addresses and names to MAC addresses.	 The following files are stored under
  the /var/join directory, unless overridden by the environment variable
  JOINSPOOL.

  *.btr	  B-trees

  *.hsh	  Hash indexes.

  The joind daemon writes a startup message and other messages previously
  described in the $JOINSPOOL/log file unless the environment variable
  JOINLOG is set, in which case the file named by that variable is used
  (NOTE: this must be an absolute filename, not a directory, nor a path
  relative filename).

  log	  The (human readable) log.

SEE ALSO
  Commands: inetd(8), joinc(8), xjoin(8)

  System calls: syslog(3)

  Files: bootptab(4), namepool(4), nets(4), server.pcy(4)

  Information: DHCP(7)

  RFC1497, RFC1541, RFC1542, RFC1533, RFC1534

Index for Section 8

Alphabetical listing for J

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