OpenSolaris 2009.06 - man page for dhcptab (opensolaris section 4)

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dhcptab(4)				   File Formats 			       dhcptab(4)

       dhcptab - DHCP configuration parameter table

       The  dhcptab  configuration table allows network administrators to organize groups of con-
       figuration parameters as macro definitions, which can then be referenced in the definition
       of other useful macros. These macros are then used by the DHCP server to return their val-
       ues to DHCP and BOOTP clients.

       The preferred method of managing the dhcptab is through the  use  of  the  dhcpmgr(1M)  or
       dhtadm(1M)  utility.  The  description  of dhcptab entries included in this manual page is
       intended for informational purposes only, and should not be used to manually edit entries.

       You can view the contents of the dhcptab using the DHCP	manager's  tabs  for  Macros  and
       Options, or using the dhtadm -P command.

   Syntax of dhcptab Entries
       The  format of a dhcptab table depends on the data store used to maintain it. However, any
       dhcptab must contain the following fields in each record:

       Name	This field identifies the macro or symbol record and is used as a search key into
		the  dhcptab  table.  The name of a macro or symbol must consist of ASCII charac-
		ters, with the length limited to 128 characters. Names can include spaces, except
		at the end of the name. The name is not case-sensitive.

       Type	This  field  specifies	the  type  of record and is used as a search key into the
		dhcptab. Currently, there are only two legal values for Type:

		m    This record is a DHCP macro definition.

		s    This record is a DHCP symbol definition. It is used  to  define  vendor  and
		     site-specific options.

       Value	This  field  contains the value for the specified type of record. For the m type,
		the value will consist of a series of symbol=value pairs, separated by the  colon
		(:) character. For the s type, the value will consist of a series of fields, sep-
		arated by a comma (,), which define a symbol's characteristics. Once  defined,	a
		symbol can be used in macro definitions.

   Symbol Characteristics
       The  Value field of a symbols definition contain the following fields describing the char-
       acteristics of a symbol:

       Context	      This field defines the context in which the  symbol  definition  is  to  be
		      used. It can have one of the following values:

		      Site			 This  symbol  defines	a  site-specific  option,
						 codes 128-254.

		      Vendor=Client Class ...	 This symbol defines  a  vendor-specific  option,
						 codes	1-254.	The  Vendor  context  takes ASCII
						 string arguments which identify the client class
						 that this vendor option is associated with. Mul-
						 tiple client class names can be specified, sepa-
						 rated	by  white space. Only those clients whose
						 client class matches one of  these  values  will
						 see  this  option.  For Sun machines, the Vendor
						 client class matches the value returned  by  the
						 command  uname  -i  on  the client, with periods
						 replacing commas.

       Code	      This field specifies the option code number associated  with  this  symbol.
		      Valid  values  are 128-254 for site-specific options, and 1-254 for vendor-
		      specific options.

       Type	      This field defines the type of data expected as a value  for  this  symbol,
		      and is not case-sensitive. Legal values are:

		      ASCII	 NVT  ASCII  text. Value is enclosed in double-quotes ("). Granu-
				 larity setting has no effect on  symbols  of  this  type,  since
				 ASCII strings have a natural granularity of one(1).

		      BOOLEAN	 No  value is associated with this data type. Presence of symbols
				 of this type denote boolean TRUE, whereas absence denotes FALSE.
				 Granularity  and  Miximum  values have no meaning for symbols of
				 this type.

		      IP	 Dotted decimal form of an  Internet  address.	Multi-IP  address
				 granularity is supported.

		      NUMBER	 An  unsigned number with a supported granularity of 1, 2, 4, and
				 8 octets.

				 Valid NUMBER types are:  UNUMBER8,  SNUMBER8,	UNUMBER16,  SNUM-
				 BER16,  UNUMBER32,  SNUMBER32,  UNUMBER64,  and  SNUMBER64.  See
				 dhcp_inittab(4) for details.

		      OCTET	 Uninterpreted ASCII representation of binary  data.  The  client
				 identifier  is  one example of an OCTET string. Valid characters
				 are 0-9, a-f, A-F. One ASCII character represents one nibble  (4
				 bits),  thus  two  ASCII characters are needed to represent an 8
				 bit quantity. The granularity setting has no effect  on  symbols
				 of  this type, since OCTET strings have a natural granularity of

				 For example, to encode a sequence of bytes with  decimal  values
				 77,  82,  5,  240,  14,  the  option  value  would be encoded as
				 4d5205f00e. A macro which supplies a value for option	code  78,
				 SLP_DA,  with	a  0  Mandatory  byte  and  Directory  Agents  at and	would appear in the dhcptab as:


       Granularity    This value specifies how many objects of Type define a single  instance  of
		      the  symbol  value. For example, the static route option is defined to be a
		      variable list of routes. Each route consists of two IP  addresses,  so  the
		      Type  is defined to be IP, and the data's granularity is defined to be 2 IP
		      addresses. The granularity field affects the IP and NUMBER data types.

       Maximum	      This value specifies the maximum items of Granularity which are permissible
		      in  a  definition  using this symbol. For example, there can only be one IP
		      address specified for a subnet mask, so the  Maximum  number  of	items  in
		      this  case  is  one(1). A  Maximum value of zero(0) means that a variable
		      number of items is permitted.

       The following example defines a site-specific option (symbol)  called  MystatRt,  of  code
       130,  type  IP,	and granularity 2, and a Maximum of 0. This definition corresponds to the
       internal definition of the static route option (StaticRt).

	 MystatRt s Site,130,IP,2,0

       The following example demonstrates how a SLP Service Scope symbol (SLP_SS)  with  a  scope
       value  of  happy  and mandatory byte set to 0 is encoded. The first octet of the option is
       the Mandatory octet, which is set either to 0 or 1. In this example, it is set to 0(00).
       The  balance  of  the  value  is  the hexidecimal ASCII code numbers representing the name
       happy, that is, 6861707079.


   Macro Definitions
       The following example illustrates a macro defined using the MystatRt  site  option  symbol
       just defined:

	 10netnis m :MystatRt=

       Macros  can  be specified in the Macro field in DHCP network tables (see dhcp_network(4)),
       which will bind particular macro definitions to specific IP addresses.

       Up to four macro definitions are consulted by the DHCP server  to  determine  the  options
       that are returned to the requesting client.

       These macros are processed in the following order:

       Client Class	    A  macro  named  using  the  ASCII representation of the client class
			    (e.g. SUNW.Ultra-30) is searched for in the dhcptab.  If  found,  its
			    symbol/value  pairs will be selected for delivery to the client. This
			    mechanism permits the network administrator to  select  configuration
			    parameters to be returned to all clients of the same class.

       Network		    A  macro  named by the dotted Internet form of the network address of
			    the client's network (for example, is searched for  in  the
			    dhcptab. If found, its symbol/value pairs will be combined with those
			    of the Client Class macro. If a symbol exists in  both  macros,  then
			    the  Network  macro  value	overrides the value defined in the Client
			    Class macro. This mechanism  permits  the  network	administrator  to
			    select  configuration parameters to be returned to all clients on the
			    same network.

       IP Address	    This macro may be named anything, but must be specified in	the  DHCP
			    network  table  for  the IP address record assigned to the requesting
			    client. If this macro is found in the dhcptab, then its  symbol/value
			    pairs  will  be combined with those of the Client Class macro and the
			    Network macro. This mechanism permits the  network	administrator  to
			    select  configuration  parameters  to  be returned to clients using a
			    particular IP address. It can also be used to deliver a macro defined
			    to include "server-specific" information by including this macro def-
			    inition in all DHCP network table entries owned by a specific server.

       Client Identifier    A macro named by the ASCII	representation	of  the  client's  unique
			    identifier	as shown in the DHCP network table (see dhcp_network(4)).
			    If found, its symbol/value pairs are  combined  to	the  sum  of  the
			    Client  Class,  Network, and IP Address macros. Any symbol collisions
			    are replaced with those specified in the client identifier macro. The
			    client mechanism permits the network administrator to select configu-
			    ration parameters to be returned to a particular  client,  regardless
			    of what network that client is connected to.

       Refer  to  System  Administration Guide: IP Services for more information about macro pro-

       Refer to the dhcp_inittab(4) man page for more information about symbols used  in  Solaris

       dhcpmgr(1M), dhtadm(1M), in.dhcpd(1M), dhcp_inittab(4), dhcp_network(4), dhcp(5)

       System Administration Guide: IP Services

       Alexander,  S.,	and R. Droms, DHCP Options and BOOTP Vendor Extensions, RFC 2132, Silicon
       Graphics, Inc., Bucknell University, March 1997.

       Droms, R., Interoperation Between DHCP and BOOTP, RFC 1534, Bucknell  University,  October

       Droms, R., Dynamic Host Configuration Protocol, RFC 2131, Bucknell University, March 1997.

       Wimer,  W.,  Clarifications  and Extensions for the Bootstrap Protocol, RFC 1542, Carnegie
       Mellon University, October 1993.

SunOS 5.11				   15 Mar 2002				       dhcptab(4)
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