1 .\" Copyright (c) 1988, 1989, 1991 Carnegie Mellon University
3 .\" $FreeBSD: src/libexec/bootpd/bootptab.5,v 1.4.2.4 2001/08/16 10:44:13 ru Exp $
4 .\" $DragonFly: src/libexec/bootpd/bootptab.5,v 1.4 2008/05/02 02:05:04 swildner Exp $
11 .Nd Internet Bootstrap Protocol server database
15 file is the configuration database file for
17 the Internet Bootstrap Protocol server.
18 Its format is similar to that of
20 in which two-character case-sensitive tag symbols are used to
21 represent host parameters. These parameter declarations are separated by
22 colons (:), with a general format of:
24 .Dl "hostname:tg=value. . . :tg=value. . . :tg=value. . . ."
28 is the actual name of a bootp client (or a "dummy entry"), and
30 is a two-character tag symbol. Dummy entries have an invalid hostname
31 (one with a "." as the first character) and are used to provide
32 default values used by other entries via the
34 mechanism. Most tags must be followed by an equals-sign
35 and a value as above. Some may also appear in a boolean form with no
38 The currently recognized tags are:
40 .Bl -tag -width xxx -compact
44 Bootfile size in 512-octet blocks
46 Cookie server address list
52 Domain name server address list
60 Bootfile home directory
62 Send client's hostname to client
64 Host hardware type (see Assigned Numbers RFC)
66 Impress server address list
70 Log server address list
72 LPR server address list
74 IEN-116 name server address list
76 NTP (time) Server (RFC 1129)
78 Reply address override
80 Resource location protocol server address list
82 Root path to mount as root
84 TFTP server address client should use
90 Table continuation (points to similar "template" host entry)
92 TFTP root directory used by "secure" TFTP servers
94 Time offset in seconds from UTC
96 Time server address list
98 Vendor magic cookie selector
102 YP (NIS) server address
105 There is also a generic tag,
109 is an RFC 1084 vendor field tag number. Thus it is possible to immediately
110 take advantage of future extensions to RFC 1084 without being forced to modify
112 first. Generic data may be represented as either a stream of hexadecimal
113 numbers or as a quoted string of
115 characters. The length of the generic
116 data is automatically determined and inserted into the proper field(s) of the
117 RFC 1084 style bootp reply.
119 The following tags take a whitespace-separated list of IP addresses:
139 tags each take a single IP address.
140 All IP addresses are specified in standard Internet "dot" notation
141 and may use decimal, octal, or hexadecimal numbers
142 (octal numbers begin with 0, hexadecimal numbers begin with '0x' or '0X').
143 Any IP addresses may alternatively be specified as a hostname, causing
145 to lookup the IP address for that host name using
146 .Xr gethostbyname 3 .
149 tag is not specified,
151 will determine the IP address using the entry name as the host name.
152 (Dummy entries use an invalid host name to avoid automatic IP lookup.)
156 tag specifies the hardware type code as either an unsigned decimal, octal, or
157 hexadecimal integer or one of the following symbolic names:
165 for 3Mb experimental Ethernet,
170 for IEEE 802 networks,
172 for Proteon ProNET Token Ring, or
177 for Chaos, ARCNET, and AX.25 Amateur Radio networks, respectively.
180 tag takes a hardware address which may be specified as a host name
181 or in numeric form. Note that the numeric form
183 be specified in hexadecimal; optional periods and/or a leading '0x' may be
184 included for readability. The
186 tag must be preceded by the
188 tag (either explicitly or implicitly; see
191 If the hardware address is not specified and the type is specified
192 as either "ethernet" or "ieee802", then
194 will try to determine the hardware address using
195 .Xr ether_hostton 3 .
197 The hostname, home directory, and bootfile are
200 optionally surrounded by double quotes ("). The client's request and the
205 symbols determine how the server fills in the bootfile field of the bootp
208 If the client provides a file name it is left as is.
211 option is specified its value is copied into the reply packet.
214 option is specified as well, its value is prepended to the
215 boot file copied into the reply packet.
216 The existence of the boot file is checked only if the
218 option is used (to determine the boot file size).
219 A reply may be sent whether or not the boot file exists.
221 Some newer versions of
223 provide a security feature to change their root directory using
229 tag may be used to inform
231 of this special root directory used by
233 (One may alternatively use the
239 tag is actually relative to the root directory specified by the
242 For example, if the real absolute path to your BOOTP client bootfile is
243 .Pa /tftpboot/bootfiles/bootimage ,
248 as its "secure" directory, then specify the following in
251 .Dl :td=/tftpboot:hd=/bootfiles:bf=bootimage:
253 If your bootfiles are located directly in
257 .Dl :td=/tftpboot:hd=/:bf=bootimage:
261 tag may be used to specify the IP address of the particular TFTP server
262 you wish the client to use. In the absence of this tag,
264 will tell the client to perform TFTP to the same machine
270 may be either a signed decimal integer specifying the client's
271 time zone offset in seconds from UTC, or the keyword
273 which uses the server's time zone offset. Specifying the
275 symbol as a boolean has the same effect as specifying
281 may be either a decimal, octal, or hexadecimal integer specifying the size of
282 the bootfile in 512-octet blocks, or the keyword
284 which causes the server to automatically calculate the bootfile size at each
285 request. As with the time offset, specifying the
287 symbol as a boolean has the same effect as specifying
291 The vendor magic cookie selector (the
293 tag) may take one of the following keywords:
295 (indicating that vendor information is determined by the client's request),
299 (which always forces an RFC 1084 style reply), or
301 (which always forces a CMU style reply).
305 tag is strictly a boolean tag; it does not take the usual equals-sign and
306 value. Its presence indicates that the hostname should be sent to RFC 1084
309 attempts to send the entire hostname as it is specified in the configuration
310 file; if this will not fit into the reply packet, the name is shortened to
311 just the host field (up to the first period, if present) and then tried.
312 In no case is an arbitrarily-truncated hostname sent (if nothing reasonable
313 will fit, nothing is sent).
315 Often, many host entries share common values for certain tags (such as name
316 servers, etc.). Rather than repeatedly specifying these tags, a full
317 specification can be listed for one host entry and shared by others via the
319 (table continuation) mechanism.
320 Often, the template entry is a dummy host which doesn't actually exist and
321 never sends bootp requests. This feature is similar to the
325 for similar terminals. Note that
329 tag symbol to appear anywhere in the host entry, unlike
331 which requires it to be the last tag. Information explicitly specified for a
332 host always overrides information implied by a
334 tag symbol, regardless of its location within the entry. The
337 tag may be the hostname or IP address of any host entry
338 previously listed in the configuration file.
340 Sometimes it is necessary to delete a specific tag after it has been inferred
343 This can be done using the construction
345 which removes the effect of
349 For example, to completely undo an IEN-116 name server specification, use
351 at an appropriate place in the configuration entry. After removal
354 a tag is eligible to be set again through the
358 Blank lines and lines beginning with "#" are ignored in the configuration
359 file. Host entries are separated from one another by newlines; a single host
360 entry may be extended over multiple lines if the lines end with a backslash
361 (\\). It is also acceptable for lines to be longer than 80 characters. Tags
362 may appear in any order, with the following exceptions: the hostname must be
363 the very first field in an entry, and the hardware type must precede the
369 .Bd -literal -offset indent
370 # Sample bootptab file (domain=andrew.cmu.edu)
373 :hd=/usr/boot:bf=null:\\
374 :ds=netserver, lancaster:\\
381 carnegie:ht=6:ha=7FF8100000AF:tc=.default:
382 baldwin:ht=1:ha=0800200159C3:tc=.default:
383 wylie:ht=1:ha=00DD00CADF00:tc=.default:
384 arnold:ht=1:ha=0800200102AD:tc=.default:
385 bairdford:ht=1:ha=08002B02A2F9:tc=.default:
386 bakerstown:ht=1:ha=08002B0287C8:tc=.default:
388 # Special domain name server and option tags for next host
389 butlerjct:ha=08002001560D:ds=128.2.13.42:\\
390 :T37=0x12345927AD3BCF:\\
391 :T99="Special ASCII string":\\
394 gastonville:ht=6:ha=7FFF81000A47:tc=.default:
395 hahntown:ht=6:ha=7FFF81000434:tc=.default:
396 hickman:ht=6:ha=7FFF810001BA:tc=.default:
397 lowber:ht=1:ha=00DD00CAF000:tc=.default:
398 mtoliver:ht=1:ha=00DD00FE1600:tc=.default:
401 .Bl -tag -width /etc/bootptab -compact
408 DARPA Internet Request For Comments RFC 951, RFC 1048, RFC 1084,