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File Formats                                      dhcp_inittab(4)

     dhcp_inittab - information repository for DHCP options

     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

        o  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).

        o  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

        o  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 ven-
     dor 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:

           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.

SunOS 5.9            Last change: 7 Jun 2001                    1

File Formats                                      dhcp_inittab(4)

     SITE  Within a specific site, all client and  server  imple-
           mentations 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.

           Each vendor may define 254 options unique to that ven-
           dor.  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

           This category is internal to the Solaris  DHCP  imple-
           mentation 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 char-
     acter is '#' are ignored.

     The fields, in order, are:

        o  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 VEN-
     DOR spaces should not overlap, or the behavior will be unde-
     fined.  See Mnemonic Identifiers for Options section of this
     man page for descriptions of the option names.

        o  Category (scope)

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

SunOS 5.9            Last change: 7 Jun 2001                    2

File Formats                                      dhcp_inittab(4)


        o  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.

        o  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

                 An 8-bit unsigned integer

                 An 8-bit signed integer

                 A 16-bit unsigned integer

                 A 16-bit signed integer

                 A 32-bit unsigned integer

                 A 32-bit signed integer

                 A 64-bit unsigned integer

                 A 64-bit signed integer

           Ip    An IP address

SunOS 5.9            Last change: 7 Jun 2001                    3

File Formats                                      dhcp_inittab(4)

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

        o  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).

        o  Maximum Number Of Items

     This value specifies the maximum items of  Granularity which
     are permissible in a definition using this symbol. For exam-
     ple, 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  per-

        o  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:

     Symbol           Code          Description
     Subnet           1             Subnet   Mask,   dotted    Internet
                                    address (IP).
     UTCoffst         2             Coordinated Universal  time  offset
     Router           3             List of Routers, IP.
     Timeserv         4             List of RFC-868 servers, IP.
     IEN116ns         5             List of IEN 116 name servers, IP.
     DNSserv          6             List of DNS name servers, IP.
     Logserv          7             List of MIT-LCS  UDP  log  servers,
     Cookie           8             List of RFC-865 cookie servers, IP.
     Lprserv          9             List  of  RFC-1179   line   printer
                                    servers, IP.
     Impress          10            List of Imagen Impress servers, IP.
     Resource         11            List of RFC-887  resource  location
                                    servers, IP.

SunOS 5.9            Last change: 7 Jun 2001                    4

File Formats                                      dhcp_inittab(4)

     Hostname         12            Client's hostname, value from hosts
     Bootsize         13            Number of 512 octet blocks in  boot
                                    image, NUMBER.
     Dumpfile         14            Path where  core  image  should  be
                                    dumped, ASCII.
     DNSdmain         15            DNS domain name, ASCII.
     Swapserv         16            Client's swap server, IP.
     Rootpath         17            Client's Root path, ASCII.
     ExtendP          18            Extensions path, ASCII.
     IpFwdF           19            IP    Forwarding    Enable/Disable,
     NLrouteF         20            Non-local Source Routing, NUMBER.
     PFilter          21            Policy Filter, IP.
     MaxIpSiz         22            Maximum datagram  Reassembly  Size,
     IpTTL            23            Default   IP    Time    to    Live,
                                    (1=<x<=255), NUMBER.
     PathTO           24            RFC-1191 Path  MTU  Aging  Timeout,
     PathTbl          25            RFC-1191 Path  MTU  Plateau  Table,
     MTU              26            Interface MTU, x>=68, NUMBER.
     SameMtuF         27            All Subnets are Local, NUMBER.
     Broadcst         28            Broadcast Address, IP.
     MaskDscF         29            Perform Mask Discovery, NUMBER.
     MaskSupF         30            Mask Supplier, NUMBER.
     RDiscvyF         31            Perform Router Discovery, NUMBER.
     RSolictS         32            Router Solicitation Address, IP.
     StaticRt         33            Static Route,  Double  IP  (network
     TrailerF         34            Trailer Encapsulation, NUMBER.
     ArpTimeO         35            ARP Cache Time out, NUMBER.
     EthEncap         36            Ethernet Encapsulation, NUMBER.
     TcpTTL           37            TCP Default Time to Live, NUMBER.
     TcpKaInt         38            TCP Keepalive Interval, NUMBER.
     TcpKaGbF         39            TCP Keepalive Garbage, NUMBER.
     NISdmain         40            NIS Domain name, ASCII.
     NISservs         41            List of NIS servers, IP.
     NTPservs         42            List of NTP servers, IP.
     NetBNms          44            List of NetBIOS Name servers, IP.
     NetBDsts         45            List   of   NetBIOS    Distribution
                                    servers, IP.
     NetBNdT          46            NetBIOS Node type  (1=B-node,  2=P,
                                    4=M, 8=H).
     NetBScop         47            NetBIOS scope, ASCII.
     XFontSrv         48            List of X Window Font servers, IP.
     XDispMgr         49            List of X Window Display  managers,
     LeaseTim         51            Lease Time  Policy,  (-1  =  PERM),

SunOS 5.9            Last change: 7 Jun 2001                    5

File Formats                                      dhcp_inittab(4)

     Message          56            Message to be displayed on  client,
     T1Time           58            Renewal (T1) time, NUMBER.
     T2Time           59            Rebinding (T2) time, NUMBER.
     NW_dmain         62            NetWare/IP Domain Name, ASCII.
     NWIPOpts         63            NetWare/IP Options, OCTET  (unknown
     NIS+dom          64            NIS+ Domain name, ASCII.
     NIS+serv         65            NIS+ servers, IP.
     TFTPsrvN         66            TFTP server hostname, ASCII.
     OptBootF         67            Optional Bootfile path, ASCII.
     MblIPAgt         68            Mobile IP Home Agent, IP.
     SMTPserv         69            Simple  Mail   Transport   Protocol
                                    Server, IP.
     POP3serv         70            Post Office Protocol (POP3) Server,
     NNTPserv         71            Network   News   Transport   Proto.
                                    (NNTP) Server, IP.
     WWWservs         72            Default WorldWideWeb Server, IP.
     Fingersv         73            Default Finger Server, IP.
     IRCservs         74            Internet Relay Chat Server, IP.
     STservs          75            StreetTalk Server, IP.
     STDAservs        76            StreetTalk    Directory     Assist.
                                    Server, IP.
     UserClas         77            User class information, ASCII.
     SLP_DA           78            Directory agent, OCTET.
     SLP_SS           79            Service scope, OCTET.
     AgentOpt         82            Agent circuit ID, OCTET.
     FQDN             89            Fully Qualified Domain Name, OCTET.
     PXEarch          93            Client system architecture, NUMBER.
     PXEnii           94            Client  Network  Device  Interface,
     PXEcid           97            UUID/GUID-based client indentifier,
     BootFile         N/A           File to Boot, ASCII.
     BootPath         N/A           Boot  path  prefix  to   apply   to
                                    client's   requested   boot   file,
     BootSrvA         N/A           Boot Server, IP.
     BootSrvN         N/A           Boot Server Hostname, ASCII.
     EchoVC           N/A           Echo Vendor Class Identifier  Flag,
     LeaseNeg         N/A           Lease    is    Negotiable     Flag,
     Include          N/A           Include listed macro values in this

     Example 1: Altering the DHCP inittab File

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File Formats                                      dhcp_inittab(4)

     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,  con-
     sisting   of  a  potentially  infinite number of pairs of IP


     See attributes(5)  for descriptions of the following  attri-

    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    | Availability                | SUNWcsr                     |
    | Interface Stability         | Evolving                    |

     dhcpinfo(1),dhcpagent(1M),  isspace(3C),  dhctab(4),  attri-
     butes(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 5.9            Last change: 7 Jun 2001                    7