BOOTPD(8)                                                            BOOTPD(8)



NAME
       bootpd, bootpgw - Internet Boot Protocol server/gateway

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

DESCRIPTION
       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 regu-
       lar  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).

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 debug-
              ging  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 sim-
              ply 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
              bootpgw.

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  This option is obsolete, but remains for com-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

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  This option is obsolete, but remains for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

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

       dumpfile
              Specifies  the name of the file that bootpd will dump its inter-
              nal 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  for-
              ward all BOOTREQUEST packets it receives (bootpgw only).

OPERATION
       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  con-
       figuration  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 com-
       poses 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  >
       0).

       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.

FILES
       /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.


BUGS
       Individual host entries must not exceed 1024 characters.


CREDITS
       This  distribution  is  currently  maintained  by   Walter   L.   Wimer
       <walt+@cmu.edu>.

       The original BOOTP server was created by Bill Croft at Stanford Univer-
       sity 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>

SEE ALSO
       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)
