NAME

dhcptags - DHCP option mnemonic mapping table

DESCRIPTION

For the most part, parameters (henceforth referred to as options) returned to the client by the DHCP/BOOTP protocol are encoded in the so-called vendor field of the BOOTP packet. Each option is identified numerically, and also carries a length specifier. The purpose of dhcptags is to indentify the type of each option, to label each with a short mnemonic text string for use by dhcpinfo(1), and to give a longer textual description.

OPTIONS

General Options

Options defined by DHCP are of three general types:

Standard

All client and server DHCP implementations agree on the semantics. These are administered by the Internet Naming Authority (IANA). These options are numbered from 1 to 127.

Site-specific

Within a specific site, all client and server implementations agree as to 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-specific

Each vendor may define 256 options unique to that vendor. The vendor is identified within a DHCP packet by the "Vendor Class" option (#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 "superencapsulated" into the vendor field (#43); within a specific DHCP packet there may be several instances of option #43.

Pseudo Options

As well as the three general types, the Solaris DHCP implementation defines certain "pseudo" options, numbered from 512 upward. These are a convenient method for referring to items which either correspond to fixed fields in the BOOTP packet (such as the siaddr field) or which, though not options themselves, are used in constructing valid options (for example, the home directory used in constructing the exact path to a boot image).

In general, the agent (see dhcpagent(1M)) knows little if anything about the semantics of any of the first three kinds of option, except for the subnet mask and broadcast address. Its only duty is to acquire and store this data and to make it available to other interested parties (see dhcpinfo(1)). The responsibility for understanding and using the data rests with these third parties. Pseudo tags, on the contrary, have a specific meaning to dhcpagent(1M), and consequently it is meaningless to add to this list. The only useful edit that can be performed on the pseudo tags is to change the textual description or the mnemonic.

USAGE

Blank lines and those whose first non-whitespace character is '# 'are ignored. Data entries are written one per line and have five fields. An individual entry cannot be continued onto another line.

The fields are (in order):

Tag number

Mnemonic identifier

Vendor class

Data type

(One from the following case insensitive values):

       byte
       octet
       int1         A 1-byte value
       int2         A 2-byte value
       int4         A 4-byte value
       string       A printable character string
       ip           An IP address
       iplist       A list of IP addresses
       int2list     A list of 2-byte values
       opaque       An array of 1-byte values
       boolean      Either true or false
Long name

Standard Option List

		Table of Standard Tags
Tag Number	Identifier	Data Type	Description

1	NetMask	ip	Subnet mask
2	UTCoffst	time	Time offset from GMT
3	Router	iplist	IP addresses of routers
4	Timesrv	iplist	IP addresses of time servers
5	IEN116ns	iplist	IP addresses of IEN=116 name servers
6	DNSserv	iplist	IP addresses of domain name servers
7	Logserv	iplist	IP addresses of remote logging servers
8	Cookie	iplist	IP address list of fortune cookie servers
9	Lprserv	iplist	IP address list of print servers
10	Impress	iplist	IP address list of impress servers
11	Resource	iplist	IP address list of RLP servers
12	Hostname	string	hostname (or nodename) of client
13	Bootsize	int16	size (in 512 blocks) of client boot file
14	Dumpfile	string	path name of Merit dump file
15	DNSdmain	string	DNS domain name
16	Swapserv	ip	ip address of swap file server
17	Rootpath	ip
18	ExtendP	string
19	IPFwdF	boolean	Enable IP forwarding
20	NLrouteF	boolean
21	PFilter	iplist	IP address list of policy filter servers
22	MaxIpSiz	int16	Maximum reassembly size of IP datagram
23	IpTTL	byte	IP time-to-live field
24	PathTO	time	PMTU timeout
25	PathTbl	int16list	PMTU plateaus
26	MTU	int16	Maximum transmission unit

			Table of Standard	Tags
	Tag Number	Identifier	Data Type	Description
	27	SameMtuF	boolean	Subnets are local
	28	Broadcst	ip	IP broadcast address of interface
	29	MaskDscf	boolean	When true perform mask discovery
	30	MaskSupF	boolean	When true supply subnet masks
	31	RDiscvyF	boolean	Perform route discovery
	32	RsolictS	ip	IP address for router solicitation
	33	StaticRt	iplist	Pairs of IP addresses for all static routes
	34	TrailerF	boolean	Perform trailer encapsulation
	35	ArpTimeO	time	Timeout interval for entry in ARP cache
	36	EthEncap	boolean	Perform Ethernet encapsulation
	37	TcpTTL	byte	TCP time-to-live
	38	TcpKaInt	time	TCP keep alive interval
	39	TcpKaGbF	boolean	Send TCP keep alive garbage octet
	40	NISdmain	string	NIS domain name
	41	NISservs	iplist	IP address list
	42	NTPservs	iplist	IP address list of NTP servers
	44	NetBNms	iplist	IP address list of NetBios name servers
	45	NetBDsts	iplist	IP address list of NetBios DG servers
	46	NetBNdT	byte	NetBios node type
	47	NetBScop	string	NetBios scope
	48	XFontSrv	iplist	IP address list of X font servers
	49	XDispMgr	iplist	IP address list of X display managers
	50	RequestIP	ip	IP address requested by client
	51	LeaseTim	time	Lease duration (secs)
	52	Overload	byte	File and/or sname fields overloaded
	53	MsgType	byte	DHCP message type
	54	ServerIp	ip	IP address of DHCP server selected by client
	55	rv	opaque	DHCP options requested by client
	56	Message	string	Message from DHCP server to client
	57	MaxMsgSz	byte	Maximum BOOTP message size acceptable
	58	T1Time	time	DHCP renewal interval
	59	T2Time	time	DHCP rebind interval
	60	Vendor	string	Client's vendor class
	61	ClientID	opaque	Client identifier
	62	NW_domain	string	Netware domain
	63	NWIPopts	string	Netware options
	64	NIS+dom	string	NIS+ domain name
	65	NIS+serv	iplist	IP address list of NIS+ servers
	66	TFTPsrvN	string	Boot file server name
	67	OptBootF	string	Path to boot file on boot file server
	68	MblIPAgt	iplist	IP address list of mobile IP home agents
	69	SMTPserv	iplist	IP address list of SMTP servers
	70	POP3serv	iplist	IP address list of POP servers
	71	NNTPserv	iplist	IP address list of NNTP servers
	72	WWWsertvs	iplist	IP address list of WWW servers
	73	Finfgersv	iplist	IP address list of Finger servers
	74	IRCservs	iplist	IP address list of IRC servers

		Table of Standard	Tags
Tag Number	Identifier	Data Type	Description

75	STservs	iplist	IP address list of StreetTalk servers
76	STDAservs	iplist	IP address list of STDA servers
77	UserClass	string	Client's user class

FILES

/etc/dhcp/dhcptags

ATTRIBUTES

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

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWcsr

SEE ALSO

dhcpinfo(1), dhcpagent(1M), attributes(5)

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

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