Sun Microsystems, Inc.
spacerspacer
spacer   www.sun.com docs.sun.com | | |  
spacer
black dot
   
A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z
    
 
File Formatsdhcp_inittab(4)


NAME

 dhcp_inittab - information repository for DHCP options

DESCRIPTION

 

The /etc/dhcp/inittab file contains information about the Dynamic Host Configuration Protocol (DHCP) options, which are network configuration parameters passed from DHCP servers to DHCP clients when a client machine uses DHCP. Since many DHCP-related commands must parse and understand these DHCP options, this file serves as a central location where information about these options may be obtained.

The DHCP inittab file provides three general pieces of information:

  • A mnemonic alias, or symbol name, for each option number. For instance, option 12 is aliased to the name Hostname. This is useful for DHCP-related programs that require human interaction, such as dhcpinfo(1).
  • Information about the syntax for each option. This includes information such as the type of the value, for example, whether it is a 16-bit integer or an IP address.
  • The policy for what options are visible to which DHCP-related programs.

The dhcp_inittab file can only be changed upon system upgrade. Only additions of SITE options (or changes to same) will be preserved during upgrade.

The VENDOR options defined here are intended for use by the Solaris DHCP client and DHCP management tools. The SUNW vendor space is owned by Sun, and changes are likely during upgrade. If you need to configure the Solaris DHCP server to support the vendor options of a different client, see dhctab(4) for details.

Each DHCP option belongs to a certain category, which roughly defines the scope of the option; for instance, an option may only be understood by certain hosts within a given site, or it may be globally understood by all DHCP clients and servers. The following categories are defined; the category names are not case-sensitive:

STANDARD
All client and server DHCP implementations agree on the semantics. These are administered by the Internet Assigned Numbers Authority (IANA). These options are numbered from 1 to 127.
SITE
Within a specific site, all client and server implementations agree on the semantics. However, at another site the type and meaning of the option may be quite different. These options are numbered from 128 to 254.
VENDOR
Each vendor may define 254 options unique to that vendor. The vendor is identified within a DHCP packet by the "Vendor Class" option, number 60. An option with a specific numeric identifier belonging to one vendor will, in general, have a type and semantics different from that of a different vendor. Vendor options are "super-encapsulated" into the vendor field number 43, as defined in RFC 2132. The dhcp_inittab file only contains Sun vendor options. Define non-Sun vendor options in the dhcptab file.
FIELD
This category allows the fixed fields within a DHCP packet to be aliased to a mnemonic name for use with dhcpinfo(1).
INTERNAL
This category is internal to the Solaris DHCP implementation and will not be further defined.

DHCP inittab Format

 

Data entries are written one per line and have seven fields; each entry provides information for one option. Each field is separated by a comma, except for the first and second, which are separated by whitespace (as defined in isspace(3C)). An entry cannot be continued onto another line. Blank lines and those whose first non-whitespace character is '#' are ignored.

The fields, in order, are:

  • Mnemonic Identifier

    The Mnemonic Identifier is a user-friendly alias for the option number; it is not case sensitive. This field must be per-category unique and should be unique across all categories. The option names in the STANDARD, SITE, and VENDOR spaces should not overlap, or the behavior will be undefined. See Mnemonic Identifiers for Options section of this man page for descriptions of the option names.

  • Category (scope)

    The Category field is one of STANDARD, SITE, VENDOR, FIELD, or INTERNAL and identifies the scope in which the option falls.

  • Option Number

    The Option Number is the number of this option when it is in a DHCP packet. This field should be per-category unique and the STANDARD and SITE fields should not have overlapping code fields or the behavior is undefined.

  • Data Type

    Data Type is one of the following values, which are not case sensitive:

    Ascii
    A printable character string
    Bool
    Has no value. Scope limited to category limited to INTERNAL. Presence of an option of this type within a Solaris configuration file represents TRUE, absence represents FALSE.
    Octet
    An array of bytes
    Unumber8
    An 8-bit unsigned integer
    Snumber8
    An 8-bit signed integer
    Unumber16
    A 16-bit unsigned integer
    Snumber16
    A 16-bit signed integer
    Unumber32
    A 32-bit unsigned integer
    Snumber32
    A 32-bit signed integer
    Unumber64
    A 64-bit unsigned integer
    Snumber64
    A 64-bit signed integer
    Ip
    An IP address

    The data type field describes an indivisible unit of the option payload, using one of the values listed above.

  • Granularity

    The Granularity field describes how many "indivisible units" in the option payload make up a whole value or item for this option. The value must be greater than zero (0) for any data type other than Bool, in which case it must be zero (0).

  • Maximum Number Of Items

    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.

  • Visibility

    The Visibility field specifies which DHCP-related programs make use of this information, and should always be defined as "sdmi" for newly added options.

Mnemonic Identifiers for Options

 

The following table maps the mnemonic identifiers used in Solaris DHCP to RFC 2132 options:

SymbolCodeDescription
Subnet1Subnet Mask, dotted Internet address (IP).
UTCoffst2Coordinated Universal time offset (seconds).
Router3List of Routers, IP.
Timeserv4List of RFC-868 servers, IP.
IEN116ns5List of IEN 116 name servers, IP.
DNSserv6List of DNS name servers, IP.
Logserv7List of MIT-LCS UDP log servers, IP.
Cookie8List of RFC-865 cookie servers, IP.
Lprserv9List of RFC-1179 line printer servers, IP.
Impress10List of Imagen Impress servers, IP.
Resource11List of RFC-887 resource location servers, IP.
Hostname12Client's hostname, value from hosts database.
Bootsize13Number of 512 octet blocks in boot image, NUMBER.
Dumpfile14Path where core image should be dumped, ASCII.
DNSdmain15DNS domain name, ASCII.
Swapserv16Client's swap server, IP.
Rootpath17Client's Root path, ASCII.
ExtendP18Extensions path, ASCII.
IpFwdF19IP Forwarding Enable/Disable, NUMBER.
NLrouteF20Non-local Source Routing, NUMBER.
PFilter21Policy Filter, IP.
MaxIpSiz22Maximum datagram Reassembly Size, NUMBER.
IpTTLtblbr23Default IP Time to Live, (1=<x<=255), NUMBER.
PathTO24RFC-1191 Path MTU Aging Timeout, NUMBER.
PathTbl25RFC-1191 Path MTU Plateau Table, NUMBER.
MTU26Interface MTU, x>=68, NUMBER.
SameMtuF27All Subnets are Local, NUMBER.
Broadcst28Broadcast Address, IP.
MaskDscF29Perform Mask Discovery, NUMBER.
MaskSupF30Mask Supplier, NUMBER.
RDiscvyF31Perform Router Discovery, NUMBER.
RSolictS32Router Solicitation Address, IP.
StaticRt33Static Route, Double IP (network router).
TrailerF34Trailer Encapsulation, NUMBER.
ArpTimeO35ARP Cache Time out, NUMBER.
EthEncap36Ethernet Encapsulation, NUMBER.
TcpTTL37TCP Default Time to Live, NUMBER.
TcpKaInt38TCP Keepalive Interval, NUMBER.
TcpKaGbF39TCP Keepalive Garbage, NUMBER.
NISdmain40NIS Domain name, ASCII.
NISservs41List of NIS servers, IP.
NTPservs42List of NTP servers, IP.
NetBNms44List of NetBIOS Name servers, IP.
NetBDsts45List of NetBIOS Distribution servers, IP.
NetBNdT46NetBIOS Node type (1=B-node, 2=P, 4=M, 8=H)
NetBScop47NetBIOS scope, ASCII.
XFontSrvtblbr48List of X Window Font servers, IP.
XDispMgr49List of X Window Display managers, IP.
LeaseTim51Lease Time Policy, (-1 = PERM), NUMBER.
Message56Message to be displayed on client, ASCII.
T1Time58Renewal (T1) time, NUMBER.
T2Time59Rebinding (T2) time, NUMBER.
NW_dmain62NetWare/IP Domain Name, ASCII.
NWIPOpts63NetWare/IP Options, OCTET (unknown type).
NIS+dom64NIS+ Domain name, ASCII.
NIS+serv65NIS+ servers, IP.
TFTPsrvN66TFTP server hostname, ASCII.
OptBootF67Optional Bootfile path, ASCII.
MblIPAgt68Mobile IP Home Agent, IP.
SMTPserv69Simple Mail Transport Protocol Server, IP.
POP3serv70Post Office Protocol (POP3) Server, IP.
NNTPserv71Network News Transport Proto. (NNTP) Server, IP.
WWWservs72Default WorldWideWeb Server, IP.
Fingersv73Default Finger Server, IP.
IRCservs74Internet Relay Chat Server, IP.
STservs75StreetTalk Server, IP.
STDAservs76StreetTalk Directory Assist. Server, IP.
UserClas77User class information, ASCII.
SLP_DAtblbr78Directory agent, OCTET.
SLP_SS79Service scope, OCTET.
AgentOpt82Agent circuit ID, OCTET.
FQDN89Fully Qualified Domain Name, OCTET.
PXEarch93Client system architecture, NUMBER.
PXEnii94Client Network Device Interface, OCTET.
PXEcid97UUID/GUID-based client indentifier, OCTET.
BootFileN/AFile to Boot, ASCII.
BootPathN/ABoot path prefix to apply to client's requested boot file, ASCII.
BootSrvAN/ABoot Server, IP.
BootSrvNN/ABoot Server Hostname, ASCII.
EchoVCN/AEcho Vendor Class Identifier Flag, (Present=TRUE)
LeaseNegN/ALease is Negotiable Flag, (Present=TRUE)
IncludeN/AInclude listed macro values in this macro.

EXAMPLES

 Example 1. Altering the DHCP inittab File
 

In general, the DHCP inittab file should only be altered to add SITE options. If other options are added, they will not be automatically carried forward when the system is upgraded. For instance:

 
ipPairs    SITE, 132, IP, 2, 0, sdmi

describes an option named ipPairs, that is in the SITE category. That is, it is defined by each individual site, and is option code 132, which is of type IP Address, consisting of a potentially infinite number of pairs of IP addresses.

FILES

 
/etc/dhcp/inittab

ATTRIBUTES

 

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPEATTRIBUTE VALUE
AvailabilitySUNWcsr
Interface StabilityEvolving

SEE ALSO

 

dhcpinfo(1),dhcpagent(1M), isspace(3C), dhctab(4), attributes(5), dhcp(5), dhcp_modules(5)

System Administration Guide: IP Services

Alexander, S., and R. Droms. RFC 2132, DHCP Options and BOOTP Vendor Extensions. Network Working Group. March 1997.

Droms, R. RFC 2131, Dynamic Host Configuration Protocol. Network Working Group. March 1997.


SunOS 5.9Go To TopLast Changed 7 Jun 2001

 
      
      
Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.