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dhcptab(4)			 File Formats			    dhcptab(4)

NAME
       dhcptab - DHCP configuration parameter table

DESCRIPTION
       The  dhcptab configuration table	allows network administrators to orga-
       nize groups of configuration 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 values 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 main-
       tain 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 characters,	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 de-
		   fine	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 sym-
	     bol=value pairs, separated	by the colon (:) character. For	the  s
	     type,  the	value will consist of a	series of fields, separated by
	     a comma (,), which	define a symbol's  characteristics.  Once  de-
	     fined, a symbol can be used in macro definitions.

   Symbol Characteristics
       The  Value  field  of a symbols definition contain the following	fields
       describing the characteristics 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 iden-
		   tify	the client class that this vendor option is associated
		   with. Multiple 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 re-
		   turned 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  (").
		   Granularity	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 ad-
		   dress 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,
		   SNUMBER16, 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	repre-
		   sents one nibble (4 bits), thus two	ASCII  characters  are
		   needed to represent an 8 bit	quantity. The granularity set-
		   ting	has no effect on symbols of  this  type,  since	 OCTET
		   strings have	a natural granularity of one (1).

       Granularity
	     This value	specifies how many objects of Type define a single in-
	     stance 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 granular-
	     ity 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

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

       10netnis	m :MystatRt=3.0.0.0 10.0.0.30:

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

       Up to four macro	definitions are	consulted by the DHCP server to	deter-
       mine 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  se-
	     lect  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, 10.0.0.0) 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 ad-
	     ministrator 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  re-
	     questing  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"  in-
	     formation	by including this macro	definition 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_net-
	     work(4)). If found, its symbol/value pairs	are  combined  to  the
	     sum of the	Client Class, Network, and IP Address macros. Any sym-
	     bol collisions are	replaced with those specified  in  the	client
	     identifier	macro. The client mechanism permits the	network	admin-
	     istrator to select	configuration parameters to be returned	 to  a
	     particular	client,	regardless of what network that	client is con-
	     nected to.

       Refer to	System Administration Guide: IP	Services for more  information
       about macro processing.

       Refer  to  the dhcp_inittab(4) man page for more	information about sym-
       bols used in Solaris DHCP.

SEE ALSO
       dhcpmgr(1M),  dhtadm(1M),  in.dhcpd(1M),	  dhcp_inittab(4),   dhcp_net-
       work(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 1993.

       Droms, R., Dynamic Host Configuration Protocol, RFC 2131, Bucknell Uni-
       versity,	March 1997.

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

SunOS 5.9			  13 Mar 2001			    dhcptab(4)

NAME | DESCRIPTION | SEE ALSO

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