man Pages(4): File Formats

dhcptags(4)

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 "super-encapsulated" 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	Timeserv	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
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 of NIS servers
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
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