1dhcptab(4) File Formats dhcptab(4)
2
6 dhcptab - DHCP configuration parameter table
7
9 The dhcptab configuration table allows network administrators to orga‐
10 nize groups of configuration parameters as macro definitions, which can
11 then be referenced in the definition of other useful macros. These
12 macros are then used by the DHCP server to return their values to DHCP
13 and BOOTP clients.
14 The preferred method of managing the dhcptab is through the use of the
17 dhcpmgr(1M) or dhtadm(1M) utility. The description of dhcptab entries
18 included in this manual page is intended for informational purposes
19 only, and should not be used to manually edit entries.
20 You can view the contents of the dhcptab using the DHCP manager's tabs
23 for Macros and Options, or using the dhtadm -P command.
24 Syntax of dhcptab Entries
26 The format of a dhcptab table depends on the data store used to main‐
27 tain it. However, any dhcptab must contain the following fields in each
28 record:
29 Name This field identifies the macro or symbol record and is used
31 as a search key into the dhcptab table. The name of a macro or
32 symbol must consist of ASCII characters, with the length lim‐
33 ited to 128 characters. Names can include spaces, except at
34 the end of the name. The name is not case-sensitive.
35 Type This field specifies the type of record and is used as a
38 search key into the dhcptab. Currently, there are only two
39 legal values for Type:
40 m This record is a DHCP macro definition.
42 s This record is a DHCP symbol definition. It is used to
45 define vendor and site-specific options.
46 Value This field contains the value for the specified type of
50 record. For the m type, the value will consist of a series of
51 symbol=value pairs, separated by the colon (:) character. For
52 the s type, the value will consist of a series of fields, sep‐
53 arated by a comma (,), which define a symbol's characteris‐
54 tics. Once defined, a symbol can be used in macro definitions.
55 Symbol Characteristics
58 The Value field of a symbols definition contain the following fields
59 describing the characteristics of a symbol:
60 Context This field defines the context in which the symbol defi‐
62 nition is to be used. It can have one of the following
63 values:
64 Site This symbol defines a site-
66 specific option, codes
67 128-254.
68 Vendor=Client Class ... This symbol defines a vendor-
71 specific option, codes 1-254.
72 The Vendor context takes
73 ASCII string arguments which
74 identify the client class
75 that this vendor option is
76 associated with. Multiple
77 client class names can be
78 specified, separated by white
79 space. Only those clients
80 whose client class matches
81 one of these values will see
82 this option. For Sun
83 machines, the Vendor client
84 class matches the value
85 returned by the command uname
86 -i on the client, with peri‐
87 ods replacing commas.
88 Code This field specifies the option code number associated
92 with this symbol. Valid values are 128-254 for site-spe‐
93 cific options, and 1-254 for vendor-specific options.
94 Type This field defines the type of data expected as a value
97 for this symbol, and is not case-sensitive. Legal values
98 are:
99 ASCII NVT ASCII text. Value is enclosed in double-
101 quotes ("). Granularity setting has no effect
102 on symbols of this type, since ASCII strings
103 have a natural granularity of one (1).
104 BOOLEAN No value is associated with this data type.
107 Presence of symbols of this type denote bool‐
108 ean TRUE, whereas absence denotes FALSE.
109 Granularity and Miximum values have no mean‐
110 ing for symbols of this type.
111 IP Dotted decimal form of an Internet address.
114 Multi-IP address granularity is supported.
115 NUMBER An unsigned number with a supported granular‐
118 ity of 1, 2, 4, and 8 octets.
119 Valid NUMBER types are: UNUMBER8, SNUMBER8,
121 UNUMBER16, SNUMBER16, UNUMBER32, SNUMBER32,
122 UNUMBER64, and SNUMBER64. See dhcp_inittab(4)
123 for details.
124 OCTET Uninterpreted ASCII representation of binary
127 data. The client identifier is one example of
128 an OCTET string. Valid characters are 0-9, a-
129 f, A-F. One ASCII character represents one
130 nibble (4 bits), thus two ASCII characters
131 are needed to represent an 8 bit quantity.
132 The granularity setting has no effect on sym‐
133 bols of this type, since OCTET strings have a
134 natural granularity of one (1).
135 For example, to encode a sequence of bytes
137 with decimal values 77, 82, 5, 240, 14, the
138 option value would be encoded as 4d5205f00e.
139 A macro which supplies a value for option
140 code 78, SLP_DA, with a 0 Mandatory byte and
141 Directory Agents at 192.168.1.5 and
142 192.168.0.133 would appear in the dhcptab
143 as:
144 slpparams
146 Macro
147 :SLP_DA=00c0a80105c0a80085:
148 Granularity This value specifies how many objects of Type define a
153 single instance of the symbol value. For example, the
154 static route option is defined to be a variable list of
155 routes. Each route consists of two IP addresses, so the
156 Type is defined to be IP, and the data's granularity is
157 defined to be 2 IP addresses. The granularity field
158 affects the IP and NUMBER data types.
159 Maximum This value specifies the maximum items of Granularity
162 which are permissible in a definition using this symbol.
163 For example, there can only be one IP address specified
164 for a subnet mask, so the Maximum number of items in
165 this case is one (1). A Maximum value of zero (0) means
166 that a variable number of items is permitted.
167 The following example defines a site-specific option (symbol) called
171 MystatRt, of code 130, type IP, and granularity 2, and a Maximum of 0.
172 This definition corresponds to the internal definition of the static
173 route option (StaticRt).
174 MystatRt s Site,130,IP,2,0
176 The following example demonstrates how a SLP Service Scope symbol
180 (SLP_SS) with a scope value of happy and mandatory byte set to 0 is
181 encoded. The first octet of the option is the Mandatory octet, which is
182 set either to 0 or 1. In this example, it is set to 0 (00). The balance
183 of the value is the hexidecimal ASCII code numbers representing the
184 name happy, that is, 6861707079.
185 SLP_SS=006861707079
187 Macro Definitions
190 The following example illustrates a macro defined using the MystatRt
191 site option symbol just defined:
192 10netnis m :MystatRt=3.0.0.0 10.0.0.30:
194 Macros can be specified in the Macro field in DHCP network tables (see
198 dhcp_network(4)), which will bind particular macro definitions to spe‐
199 cific IP addresses.
200 Up to four macro definitions are consulted by the DHCP server to deter‐
203 mine the options that are returned to the requesting client.
204 These macros are processed in the following order:
207 Client Class A macro named using the ASCII representation of
209 the client class (e.g. SUNW.Ultra-30) is searched
210 for in the dhcptab. If found, its symbol/value
211 pairs will be selected for delivery to the client.
212 This mechanism permits the network administrator
213 to select configuration parameters to be returned
214 to all clients of the same class.
215 Network A macro named by the dotted Internet form of the
218 network address of the client's network (for exam‐
219 ple, 10.0.0.0) is searched for in the dhcptab. If
220 found, its symbol/value pairs will be combined
221 with those of the Client Class macro. If a symbol
222 exists in both macros, then the Network macro
223 value overrides the value defined in the Client
224 Class macro. This mechanism permits the network
225 administrator to select configuration parameters
226 to be returned to all clients on the same network.
227 IP Address This macro may be named anything, but must be
230 specified in the DHCP network table for the IP
231 address record assigned to the requesting client.
232 If this macro is found in the dhcptab, then its
233 symbol/value pairs will be combined with those of
234 the Client Class macro and the Network macro. This
235 mechanism permits the network administrator to
236 select configuration parameters to be returned to
237 clients using a particular IP address. It can also
238 be used to deliver a macro defined to include
239 "server-specific" information by including this
240 macro definition in all DHCP network table entries
241 owned by a specific server.
242 Client Identifier A macro named by the ASCII representation of the
245 client's unique identifier as shown in the DHCP
246 network table (see dhcp_network(4)). If found, its
247 symbol/value pairs are combined to the sum of the
248 Client Class, Network, and IP Address macros. Any
249 symbol collisions are replaced with those speci‐
250 fied in the client identifier macro. The client
251 mechanism permits the network administrator to
252 select configuration parameters to be returned to
253 a particular client, regardless of what network
254 that client is connected to.
255 Refer to System Administration Guide: IP Services for more information
259 about macro processing.
260 Refer to the dhcp_inittab(4) man page for more information about sym‐
263 bols used in Solaris DHCP.
264
266 dhcpmgr(1M), dhtadm(1M), in.dhcpd(1M), dhcp_inittab(4), dhcp_net‐
267 work(4), dhcp(5)
268 System Administration Guide: IP Services
271 Alexander, S., and R. Droms, DHCP Options and BOOTP Vendor Extensions,
274 RFC 2132, Silicon Graphics, Inc., Bucknell University, March 1997.
275 Droms, R., Interoperation Between DHCP and BOOTP, RFC 1534, Bucknell
278 University, October 1993.
279 Droms, R., Dynamic Host Configuration Protocol, RFC 2131, Bucknell Uni‐
282 versity, March 1997.
283 Wimer, W., Clarifications and Extensions for the Bootstrap Protocol,
286 RFC 1542, Carnegie Mellon University, October 1993.
287SunOS 5.11 15 Mar 2002 dhcptab(4)