bootpd, bootpgw - Internet Boot Protocol server/gateway
] [ -i -s -t timeout
-d level -c chdir-path
] [ bootptab
] [ -i -s -t timeout
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.
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.
) on another subnet. While either bootpd
will forward BOOTREPLY packets, only bootpgw
will forward BOOTREQUEST
One host on each network segment is normally configured to run either
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
) 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
) in "standalone
mode" (without inetd
) by simply invoking it from a shell like any
other regular command. Standalone mode is particularly useful when
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
, for example.) Standalone mode is less useful for
which has very little start up delay because it does not read a
Either program automatically detects whether it was invoked from inetd or from a
shell and automatically selects the appropriate mode. The -s
option may be used to force standalone or inetd mode respectively
- -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 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.
- Force inetd mode. This option is obsolete, but remains for
compatibility with older versions of bootpd.
- Force standalone mode. This option is obsolete, but remains
for compatibility with older versions of bootpd.
- Print version and exit.
- 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.
- 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.
- Specifies the name of a BOOTP server to which
bootpgw will forward all BOOTREQUEST packets it receives
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.
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.
is started it reads a configuration file, (normally
) 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 conditions.
receives a BOOTREQUEST packet, it looks for a database entry
matching the client request. If the client is known, bootpd
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).
is compiled with the -DDEBUG option, receipt of a
signal causes it to dump its internal database to the file
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/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
values default to boopts=67 and bootpc=68.
- Database file read by bootpd.
- Debugging dump file created by bootpd.
- Internet service numbers.
- Current directory typically used by the TFTP server and
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
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 <email@example.com>
John Brezak <firstname.lastname@example.org>
Frank da Cruz <email@example.com>
David R. Linn <firstname.lastname@example.org>
Jim McKim <email@example.com>
Pauline Middelink <firstname.lastname@example.org>
Martin Schulze <email@example.com>
Gordon W. Ross <firstname.lastname@example.org>
Jason Zions <email@example.com>
DARPA Internet Request For Comments:
- Bootstrap Protocol
- Clarifications and Extensions for the Bootstrap
- DHCP Options and BOOTP Vendor Extensions