1 .\" Copyright (c) 1988, 1989, 1991 Carnegie Mellon University
8 .Nd Internet Bootstrap Protocol server database
12 file is the configuration database file for
14 the Internet Bootstrap Protocol server.
15 Its format is similar to that of
17 in which two-character case-sensitive tag symbols are used to
18 represent host parameters.
19 These parameter declarations are separated by
20 colons (:), with a general format of:
22 .Dl "hostname:tg=value. . . :tg=value. . . :tg=value. . . ."
26 is the actual name of a bootp client (or a "dummy entry"), and
28 is a two-character tag symbol.
29 Dummy entries have an invalid hostname
30 (one with a "." as the first character) and are used to provide
31 default values used by other entries via the
34 Most tags must be followed by an equals-sign
36 Some may also appear in a boolean form with no
39 The currently recognized tags are:
41 .Bl -tag -width xxx -compact
45 Bootfile size in 512-octet blocks
47 Cookie server address list
53 Domain name server address list
61 Bootfile home directory
63 Send client's hostname to client
65 Host hardware type (see Assigned Numbers RFC)
67 Impress server address list
71 Log server address list
73 LPR server address list
75 IEN-116 name server address list
77 NTP (time) Server (RFC 1129)
79 Reply address override
81 Resource location protocol server address list
83 Root path to mount as root
85 TFTP server address client should use
91 Table continuation (points to similar "template" host entry)
93 TFTP root directory used by "secure" TFTP servers
95 Time offset in seconds from UTC
97 Time server address list
99 Vendor magic cookie selector
103 YP (NIS) server address
106 There is also a generic tag,
110 is an RFC1084 vendor field tag number.
111 Thus it is possible to immediately
112 take advantage of future extensions to RFC1084 without being forced to modify
115 Generic data may be represented as either a stream of hexadecimal
116 numbers or as a quoted string of
119 The length of the generic
120 data is automatically determined and inserted into the proper field(s) of the
121 RFC1084-style bootp reply.
123 The following tags take a whitespace-separated list of IP addresses:
143 tags each take a single IP address.
144 All IP addresses are specified in standard Internet "dot" notation
145 and may use decimal, octal, or hexadecimal numbers
146 (octal numbers begin with 0, hexadecimal numbers begin with '0x' or '0X').
147 Any IP addresses may alternatively be specified as a hostname, causing
149 to lookup the IP address for that host name using
150 .Xr gethostbyname 3 .
153 tag is not specified,
155 will determine the IP address using the entry name as the host name.
156 (Dummy entries use an invalid host name to avoid automatic IP lookup.)
160 tag specifies the hardware type code as either an unsigned decimal, octal, or
161 hexadecimal integer or one of the following symbolic names:
169 for 3Mb experimental Ethernet,
174 for IEEE 802 networks,
176 for Proteon ProNET Token Ring, or
181 for Chaos, ARCNET, and AX.25 Amateur Radio networks, respectively.
184 tag takes a hardware address which may be specified as a host name
186 Note that the numeric form
188 be specified in hexadecimal; optional periods and/or a leading '0x' may be
189 included for readability.
192 tag must be preceded by the
194 tag (either explicitly or implicitly; see
197 If the hardware address is not specified and the type is specified
198 as either "ethernet" or "ieee802", then
200 will try to determine the hardware address using
201 .Xr ether_hostton 3 .
203 The hostname, home directory, and bootfile are
206 optionally surrounded by double quotes (").
207 The client's request and the
212 symbols determine how the server fills in the bootfile field of the bootp
215 If the client provides a file name it is left as is.
218 option is specified its value is copied into the reply packet.
221 option is specified as well, its value is prepended to the
222 boot file copied into the reply packet.
223 The existence of the boot file is checked only if the
225 option is used (to determine the boot file size).
226 A reply may be sent whether or not the boot file exists.
228 Some newer versions of
230 provide a security feature to change their root directory using
236 tag may be used to inform
238 of this special root directory used by
240 (One may alternatively use the
246 tag is actually relative to the root directory specified by the
249 For example, if the real absolute path to your BOOTP client bootfile is
250 .Pa /tftpboot/bootfiles/bootimage ,
255 as its "secure" directory, then specify the following in
258 .Dl :td=/tftpboot:hd=/bootfiles:bf=bootimage:
260 If your bootfiles are located directly in
264 .Dl :td=/tftpboot:hd=/:bf=bootimage:
268 tag may be used to specify the IP address of the particular TFTP server
269 you wish the client to use.
270 In the absence of this tag,
272 will tell the client to perform TFTP to the same machine
278 may be either a signed decimal integer specifying the client's
279 time zone offset in seconds from UTC, or the keyword
281 which uses the server's time zone offset.
284 symbol as a boolean has the same effect as specifying
290 may be either a decimal, octal, or hexadecimal integer specifying the size of
291 the bootfile in 512-octet blocks, or the keyword
293 which causes the server to automatically calculate the bootfile size at each
295 As with the time offset, specifying the
297 symbol as a boolean has the same effect as specifying
301 The vendor magic cookie selector (the
303 tag) may take one of the following keywords:
305 (indicating that vendor information is determined by the client's request),
309 (which always forces an RFC1084-style reply), or
311 (which always forces a CMU-style reply).
315 tag is strictly a boolean tag; it does not take the usual equals-sign and
317 Its presence indicates that the hostname should be sent to RFC1084
320 attempts to send the entire hostname as it is specified in the configuration
321 file; if this will not fit into the reply packet, the name is shortened to
322 just the host field (up to the first period, if present) and then tried.
323 In no case is an arbitrarily-truncated hostname sent (if nothing reasonable
324 will fit, nothing is sent).
326 Often, many host entries share common values for certain tags (such as name
328 Rather than repeatedly specifying these tags, a full
329 specification can be listed for one host entry and shared by others via the
331 (table continuation) mechanism.
332 Often, the template entry is a dummy host which does not actually exist and
333 never sends bootp requests.
334 This feature is similar to the
338 for similar terminals.
343 tag symbol to appear anywhere in the host entry, unlike
345 which requires it to be the last tag.
346 Information explicitly specified for a
347 host always overrides information implied by a
349 tag symbol, regardless of its location within the entry.
353 tag may be the hostname or IP address of any host entry
354 previously listed in the configuration file.
356 Sometimes it is necessary to delete a specific tag after it has been inferred
359 This can be done using the construction
361 which removes the effect of
365 For example, to completely undo an IEN-116 name server specification, use
367 at an appropriate place in the configuration entry.
371 a tag is eligible to be set again through the
375 Blank lines and lines beginning with "#" are ignored in the configuration
377 Host entries are separated from one another by newlines; a single host
378 entry may be extended over multiple lines if the lines end with a backslash
380 It is also acceptable for lines to be longer than 80 characters.
382 may appear in any order, with the following exceptions: the hostname must be
383 the very first field in an entry, and the hardware type must precede the
389 .Bd -literal -offset indent
390 # Sample bootptab file (domain=andrew.cmu.edu)
393 :hd=/usr/boot:bf=null:\\
394 :ds=netserver, lancaster:\\
401 carnegie:ht=6:ha=7FF8100000AF:tc=.default:
402 baldwin:ht=1:ha=0800200159C3:tc=.default:
403 wylie:ht=1:ha=00DD00CADF00:tc=.default:
404 arnold:ht=1:ha=0800200102AD:tc=.default:
405 bairdford:ht=1:ha=08002B02A2F9:tc=.default:
406 bakerstown:ht=1:ha=08002B0287C8:tc=.default:
408 # Special domain name server and option tags for next host
409 butlerjct:ha=08002001560D:ds=128.2.13.42:\\
410 :T37=0x12345927AD3BCF:\\
411 :T99="Special ASCII string":\\
414 gastonville:ht=6:ha=7FFF81000A47:tc=.default:
415 hahntown:ht=6:ha=7FFF81000434:tc=.default:
416 hickman:ht=6:ha=7FFF810001BA:tc=.default:
417 lowber:ht=1:ha=00DD00CAF000:tc=.default:
418 mtoliver:ht=1:ha=00DD00FE1600:tc=.default:
421 .Bl -tag -width /etc/bootptab -compact
428 DARPA Internet Request For Comments RFC951, RFC1048, RFC1084, Assigned Numbers