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BOOTPD(8)                   System Manager's Manual                  BOOTPD(8)

       bootpd, bootpgw - Internet Boot Protocol server/gateway

       bootpd [ -i -s -t timeout -d level -c chdir-path ] [ bootptab [
       dumpfile ] ]
       bootpgw [ -i -s -t timeout -d level ] server

       Bootpd implements an Internet Bootstrap Protocol (BOOTP) server as
       defined in RFC951, RFC1532, and RFC1533.  Bootpgw implements a simple
       BOOTP gateway which can be used to forward requests and responses
       between clients on one subnet and a BOOTP server (i.e.  bootpd) on
       another subnet. While either bootpd or bootpgw will forward BOOTREPLY
       packets, only bootpgw will forward BOOTREQUEST packets.

       One host on each network segment is normally configured to run either
       bootpd or bootpgw from inetd by including one of the following lines in
       the file /etc/inetd.conf:

              bootps dgram udp wait root /usr/sbin/bootpd bootpd bootptab
              bootps dgram udp wait root /usr/sbin/bootpgw bootpgw server

       This mode of operation is referred to as "inetd mode" and causes bootpd
       (or bootpgw) to be started only when a boot request arrives.  If it
       does not receive another packet within fifteen minutes of the last one
       it received, it will exit to conserve system resources.  The -t option
       controls this timeout (see OPTIONS).

       It is also possible to run bootpd (or bootpgw) in "standalone mode"
       (without inetd) by simply invoking it from a shell like any other
       regular command.  Standalone mode is particularly useful when bootpd is
       used with a large configuration database, where the start up delay
       might otherwise prevent timely response to client requests.  (Automatic
       start up in standalone mode can be done by invoking bootpd from within
       /etc/rc.local, for example.)  Standalone mode is less useful for
       bootpgw which has very little start up delay because it does not read a
       configuration file.

       Either program automatically detects whether it was invoked from inetd
       or from a shell and automatically selects the appropriate mode.  The -s
       or -i option may be used to force standalone or inetd mode respectively
       (see OPTIONS).

       -t timeout
              Specifies the timeout value (in minutes) that a bootpd or
              bootpgw process will wait for a BOOTP packet before exiting.  If
              no packets are received for timeout minutes, then the program
              will exit.  A timeout value of zero means "run forever".  In
              standalone mode, this option is forced to zero.

       -d debug-level
              Sets the debug-level variable that controls the amount of
              debugging messages generated.  For example, -d4 or -d 4 will set
              the debugging level to 4.  For compatibility with older versions
              of bootpd, omitting the numeric parameter (i.e. just -d) will
              simply increment the debug level by one.

       -c chdir-path
              Sets the current directory used by bootpd while checking the
              existence and size of client boot files.  This is useful when
              client boot files are specified as relative pathnames, and
              bootpd needs to use the same current directory as the TFTP
              server (typically /tftpboot).  This option is not recognized by

       -i     Force inetd mode.  This option is obsolete, but remains for
              compatibility with older versions of bootpd.

       -s     Force standalone mode.  This option is obsolete, but remains for
              compatibility with older versions of bootpd.

              Specifies the name of the configuration file from which bootpd
              loads its database of known clients and client options (bootpd

              Specifies the name of the file that bootpd will dump its
              internal database into when it receives a SIGUSR1 signal (bootpd
              only).  This option is only recognized if bootpd was compiled
              with the -DDEBUG flag.

       server Specifies the name of a BOOTP server to which bootpgw will
              forward all BOOTREQUEST packets it receives (bootpgw only).

       Both bootpd and bootpgw operate similarly in that both listen for any
       packets sent to the bootps port, and both simply forward any BOOTREPLY
       packets.  They differ in their handling of BOOTREQUEST packets.

       When bootpgw is started, it determines the address of a BOOTP server
       whose name is provided as a command line parameter.  When bootpgw
       receives a BOOTREQUEST packet, it sets the "gateway address" and "hop
       count" fields in the packet and forwards the packet to the BOOTP server
       at the address determined earlier.  Requests are forwarded only if they
       indicate that the client has been waiting for at least three seconds.

       When bootpd is started it reads a configuration file, (normally
       /etc/bootptab) that initializes the internal database of known clients
       and client options.  This internal database is reloaded from the
       configuration file when bootpd receives a hangup signal (SIGHUP) or
       when it discovers that the configuration file has changed.

       When bootpd receives a BOOTREQUEST packet, it looks for a database
       entry matching the client request.  If the client is known, bootpd
       composes a BOOTREPLY packet using the database entry found above, and
       sends the reply to the client (possibly using a gateway).  If the
       client is unknown, the request is discarded (with a notice if debug >

       If bootpd is compiled with the -DDEBUG option, receipt of a SIGUSR1
       signal causes it to dump its internal database to the file
       /etc/bootpd.dump or the dumpfile specified as a command line parameter.

       During initialization, both programs determine the UDP port numbers to
       be used by calling getservbyname (which normally uses /etc/services).
       Two service names (and port numbers) are used:

              bootps - BOOTP Server listening port
              bootpc - BOOTP Client destination port

       If the port numbers cannot be determined using getservbyname then the
       values default to bootps=67 and bootpc=68.

       /etc/bootptab       Database file read by bootpd.

       /etc/bootpd.dump    Debugging dump file created by bootpd.

       /etc/services       Internet service numbers.

       /tftpboot           Current directory typically used by the TFTP server
                           and bootpd.

       Individual host entries must not exceed 1024 characters.

       This distribution is currently maintained by Walter L. Wimer

       The original BOOTP server was created by Bill Croft at Stanford
       University in January 1986.

       The current version of bootpd is primarily the work of David Kovar,
       Drew D. Perkins, and Walter L. Wimer, at Carnegie Mellon University.

       Enhancements and bug-fixes have been contributed by:
              (in alphabetical order)
              Danny Backx <db@sunbim.be>
              John Brezak <brezak@ch.hp.com>
              Frank da Cruz <fdc@cc.columbia.edu>
              David R. Linn <drl@vuse.vanderbilt.edu>
              Jim McKim <mckim@lerc.nasa.gov>
              Gordon W. Ross <gwr@mc.com>
              Jason Zions <jazz@hal.com>

       bootptab(5), inetd(8), tftpd(8)

       DARPA Internet Request For Comments:

       RFC951    Bootstrap Protocol

       RFC1532   Clarifications and Extensions for the Bootstrap Protocol

       RFC1533   DHCP Options and BOOTP Vendor Extensions

Carnegie Mellon University     November 06, 1993                     BOOTPD(8)