BOOTPD(8)						    Carnegie Mellon University							 BOOTPD(8)

NAME

       bootpd, bootpgw - Internet Boot Protocol server/gateway

SYNOPSIS

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

DESCRIPTION

       Bootpd  implements an Internet Bootstrap Protocol (BOOTP) server as defined in RFC951, RFC1532, and RFC1533. This server also provides some
       extension to support the static part of Dynamic Host Configuration Protocol (DHCP) as specified in RFC1533. DHCP is used by Windows NT  and
       95.   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 below).

       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 bootgw 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 pack-
	      ets are received for timeout seconds, 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 bootpgw.

       -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.

       -v     Print version and exit.

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

       dumpfile
	      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).

OPERATION

       Both  bootpd and bootpgw operate similarly in that both listen for any packets sent to the bootps port, and both simply forward any BOOTRE-
       PLY 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.  Note that any changes to the configuration file should be atomic to avoid race condi-
       tions.

       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
       /tmp/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(3) (which normally uses /etc/ser-
       vices).	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 boopts=67 and bootpc=68.

FILES

       /etc/bootptab
	      Database file read by bootpd.

       /tmp/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 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>
	      Pauline Middelink <middelin@calvin.polyware.iaf.nl>
	      Martin Schulze <joey@infodrom.north.de>
	      Gordon W. Ross <gwr@mc.com>
	      Jason Zions <jazz@hal.com>

SEE ALSO

       bootptab(5), services(5), inetd(8), inetd.conf(5), 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

Version 2.4.3							 12 November 1995							 BOOTPD(8)