0	Pad	0	None	[RFC2132]
1	Subnet Mask	4	Subnet Mask Value	[RFC2132]
2	Time Offset	4	Time Offset in Seconds from UTC (note: deprecated by 100 and 101)	[RFC2132]
3	Router	N	N/4 Router addresses	[RFC2132]
4	Time Server	N	N/4 Timeserver addresses	[RFC2132]
5	Name Server	N	N/4 IEN-116 Server addresses	[RFC2132]
6	Domain Server	N	N/4 DNS Server addresses	[RFC2132]
7	Log Server	N	N/4 Logging Server addresses	[RFC2132]
8	Quotes Server	N	N/4 Quotes Server addresses	[RFC2132]
9	LPR Server	N	N/4 Printer Server addresses	[RFC2132]
10	Impress Server	N	N/4 Impress Server addresses	[RFC2132]
11	RLP Server	N	N/4 RLP Server addresses	[RFC2132]
12	Hostname	N	Hostname string	[RFC2132]
13	Boot File Size	2	Size of boot file in 512 byte chunks	[RFC2132]
14	Merit Dump File	N	Client to dump and name the file to dump it to	[RFC2132]
15	Domain Name	N	The DNS domain name of the client	[RFC2132]
16	Swap Server	N	Swap Server address	[RFC2132]
17	Root Path	N	Path name for root disk	[RFC2132]
18	Extension File	N	Path name for more BOOTP info	[RFC2132]
19	Forward On/Off	1	Enable/Disable IP Forwarding	[RFC2132]
20	SrcRte On/Off	1	Enable/Disable Source Routing	[RFC2132]
21	Policy Filter	N	Routing Policy Filters	[RFC2132]
22	Max DG Assembly	2	Max Datagram Reassembly Size	[RFC2132]
23	Default IP TTL	1	Default IP Time to Live	[RFC2132]
24	MTU Timeout	4	Path MTU Aging Timeout	[RFC2132]
25	MTU Plateau	N	Path MTU Plateau Table	[RFC2132]
26	MTU Interface	2	Interface MTU Size	[RFC2132]
27	MTU Subnet	1	All Subnets are Local	[RFC2132]
28	Broadcast Address	4	Broadcast Address	[RFC2132]
29	Mask Discovery	1	Perform Mask Discovery	[RFC2132]
30	Mask Supplier	1	Provide Mask to Others	[RFC2132]
31	Router Discovery	1	Perform Router Discovery	[RFC2132]
32	Router Request	4	Router Solicitation Address	[RFC2132]
33	Static Route	N	Static Routing Table	[RFC2132]
34	Trailers	1	Trailer Encapsulation	[RFC2132]
35	ARP Timeout	4	ARP Cache Timeout	[RFC2132]
36	Ethernet	1	Ethernet Encapsulation	[RFC2132]
37	Default TCP TTL	1	Default TCP Time to Live	[RFC2132]
38	Keepalive Time	4	TCP Keepalive Interval	[RFC2132]
39	Keepalive Data	1	TCP Keepalive Garbage	[RFC2132]
40	NIS Domain	N	NIS Domain Name	[RFC2132]
41	NIS Servers	N	NIS Server Addresses	[RFC2132]
42	NTP Servers	N	NTP Server Addresses	[RFC2132]
43	Vendor Specific	N	Vendor Specific Information	[RFC2132]
44	NETBIOS Name Srv	N	NETBIOS Name Servers	[RFC2132]
45	NETBIOS Dist Srv	N	NETBIOS Datagram Distribution	[RFC2132]
46	NETBIOS Node Type	1	NETBIOS Node Type	[RFC2132]
47	NETBIOS Scope	N	NETBIOS Scope	[RFC2132]
48	X Window Font	N	X Window Font Server	[RFC2132]
49	X Window Manager	N	X Window Display Manager	[RFC2132]
50	Address Request	4	Requested IP Address	[RFC2132]
51	Address Time	4	IP Address Lease Time	[RFC2132]
52	Overload	1	Overload "sname" or "file"	[RFC2132]
53	DHCP Msg Type	1	DHCP Message Type	[RFC2132]
54	DHCP Server Id	4	DHCP Server Identification	[RFC2132]
55	Parameter List	N	Parameter Request List	[RFC2132]
56	DHCP Message	N	DHCP Error Message	[RFC2132]
57	DHCP Max Msg Size	2	DHCP Maximum Message Size	[RFC2132]
58	Renewal Time	4	DHCP Renewal (T1) Time	[RFC2132]
59	Rebinding Time	4	DHCP Rebinding (T2) Time	[RFC2132]
60	Class Id	N	Class Identifier	[RFC2132]
61	Client Id	N	Client Identifier	[RFC2132]
62	NetWare/IP Domain	N	NetWare/IP Domain Name	[RFC2242]
63	NetWare/IP Option	N	NetWare/IP sub Options	[RFC2242]
64	NIS-Domain-Name	N	NIS+ v3 Client Domain Name	[RFC2132]
65	NIS-Server-Addr	N	NIS+ v3 Server Addresses	[RFC2132]
66	Server-Name	N	TFTP Server Name	[RFC2132]
67	Bootfile-Name	N	Boot File Name	[RFC2132]
68	Home-Agent-Addrs	N	Home Agent Addresses	[RFC2132]
69	SMTP-Server	N	Simple Mail Server Addresses	[RFC2132]
70	POP3-Server	N	Post Office Server Addresses	[RFC2132]
71	NNTP-Server	N	Network News Server Addresses	[RFC2132]
72	WWW-Server	N	WWW Server Addresses	[RFC2132]
73	Finger-Server	N	Finger Server Addresses	[RFC2132]
74	IRC-Server	N	Chat Server Addresses	[RFC2132]
75	StreetTalk-Server	N	StreetTalk Server Addresses	[RFC2132]
76	STDA-Server	N	ST Directory Assist. Addresses	[RFC2132]
77	User-Class	N	User Class Information	[RFC3004]
78	Directory Agent	N	directory agent information	[RFC2610]
79	Service Scope	N	service location agent scope	[RFC2610]
80	Rapid Commit	0	Rapid Commit	[RFC4039]
81	Client FQDN	N	Fully Qualified Domain Name	[RFC4702]
82	Relay Agent Information	N	Relay Agent Information	[RFC3046]
83	iSNS	N	Internet Storage Name Service	[RFC4174]
84	REMOVED/Unassigned			[RFC3679]
85	NDS Servers	N	Novell Directory Services	[RFC2241]
86	NDS Tree Name	N	Novell Directory Services	[RFC2241]
87	NDS Context	N	Novell Directory Services	[RFC2241]
88	BCMCS Controller Domain Name list			[RFC4280]
89	BCMCS Controller IPv4 address option			[RFC4280]
90	Authentication	N	Authentication	[RFC3118]
91	client-last-transaction-time option			[RFC4388]
92	associated-ip option			[RFC4388]
93	Client System	N	Client System Architecture	[RFC4578]
94	Client NDI	N	Client Network Device Interface	[RFC4578]
95	LDAP	N	Lightweight Directory Access Protocol	[RFC3679]
96	REMOVED/Unassigned			[RFC3679]
97	UUID/GUID	N	UUID/GUID-based Client Identifier	[RFC4578]
98	User-Auth	N	Open Group's User Authentication	[RFC2485]
99	GEOCONF_CIVIC			[RFC4776]
100	PCode	N	IEEE 1003.1 TZ String	[RFC4833]
101	TCode	N	Reference to the TZ Database	[RFC4833]
102-107	REMOVED/Unassigned			[RFC3679]
108	IPv6-Only Preferred	4	Number of seconds that DHCPv4 should be disabled	[RFC8925]
109	OPTION_DHCP4O6_S46_SADDR	16	DHCPv4 over DHCPv6 Softwire Source Address Option	[RFC8539]
110	REMOVED/Unassigned			[RFC3679]
111	Unassigned			[RFC3679]
112	Netinfo Address	N	NetInfo Parent Server Address	[RFC3679]
113	Netinfo Tag	N	NetInfo Parent Server Tag	[RFC3679]
114	DHCP Captive-Portal	N	DHCP Captive-Portal	[RFC8910]
115	REMOVED/Unassigned			[RFC3679]
116	Auto-Config	N	DHCP Auto-Configuration	[RFC2563]
117	Name Service Search	N	Name Service Search	[RFC2937]
118	Subnet Selection Option	4	Subnet Selection Option	[RFC3011]
119	Domain Search	N	DNS domain search list	[RFC3397]
120	SIP Servers DHCP Option	N	SIP Servers DHCP Option	[RFC3361]
121	Classless Static Route Option	N	Classless Static Route Option	[RFC3442]
122	CCC	N	CableLabs Client Configuration	[RFC3495]
123	GeoConf Option	16	GeoConf Option	[RFC6225]
124	V-I Vendor Class		Vendor-Identifying Vendor Class	[RFC3925]
125	V-I Vendor-Specific Information		Vendor-Identifying Vendor-Specific Information	[RFC3925]
126	Removed/Unassigned			[RFC3679]
127	Removed/Unassigned			[RFC3679]
128	PXE - undefined (vendor specific)			[RFC4578]
128	Etherboot signature. 6 bytes: E4:45:74:68:00:00			
128	DOCSIS "full security" server IP address			
128	TFTP Server IP address (for IP Phone software load)			
129	PXE - undefined (vendor specific)			[RFC4578]
129	Kernel options. Variable length string			
129	Call Server IP address			
130	PXE - undefined (vendor specific)			[RFC4578]
130	Ethernet interface. Variable length string.			
130	Discrimination string (to identify vendor)			
131	PXE - undefined (vendor specific)			[RFC4578]
131	Remote statistics server IP address			
132	PXE - undefined (vendor specific)			[RFC4578]
132	IEEE 802.1Q VLAN ID			
133	PXE - undefined (vendor specific)			[RFC4578]
133	IEEE 802.1D/p Layer 2 Priority			
134	PXE - undefined (vendor specific)			[RFC4578]
134	Diffserv Code Point (DSCP) for VoIP signalling and media streams			
135	PXE - undefined (vendor specific)			[RFC4578]
135	HTTP Proxy for phone-specific applications			
136	OPTION_PANA_AGENT			[RFC5192]
137	OPTION_V4_LOST			[RFC5223]
138	OPTION_CAPWAP_AC_V4	N	CAPWAP Access Controller addresses	[RFC5417]
139	OPTION-IPv4_Address-MoS	N	a series of suboptions	[RFC5678]
140	OPTION-IPv4_FQDN-MoS	N	a series of suboptions	[RFC5678]
141	SIP UA Configuration Service Domains	N	List of domain names to search for SIP User Agent Configuration	[RFC6011]
142	OPTION-IPv4_Address-ANDSF	N	ANDSF IPv4 Address Option for DHCPv4	[RFC6153]
143	OPTION_V4_SZTP_REDIRECT	N	This option provides a list of URIs for SZTP bootstrap servers	[RFC8572]
144	GeoLoc	16	Geospatial Location with Uncertainty	[RFC6225]
145	FORCERENEW_NONCE_CAPABLE	1	Forcerenew Nonce Capable	[RFC6704]
146	RDNSS Selection	N	Information for selecting RDNSS	[RFC6731]
147	OPTION_V4_DOTS_RI	N	The name of the peer DOTS agent.	[RFC8973]
148	OPTION_V4_DOTS_ADDRESS	N (the minimal length is 4)	N/4 IPv4 addresses of peer DOTS agent(s).	[RFC8973]
149	Unassigned			[RFC3942]
150	TFTP server address			[RFC5859]
150	Etherboot			
150	GRUB configuration path name			
151	status-code	N+1	Status code and optional N byte text message describing status.	[RFC6926]
152	base-time	4	Absolute time (seconds since Jan 1, 1970) message was sent.	[RFC6926]
153	start-time-of-state	4	Number of seconds in the past when client entered current state.	[RFC6926]
154	query-start-time	4	Absolute time (seconds since Jan 1, 1970) for beginning of query.	[RFC6926]
155	query-end-time	4	Absolute time (seconds since Jan 1, 1970) for end of query.	[RFC6926]
156	dhcp-state	1	State of IP address.	[RFC6926]
157	data-source	1	Indicates information came from local or remote server.	[RFC6926]
158	OPTION_V4_PCP_SERVER	Variable; the minimum length is 5.	Includes one or multiple lists of PCP server IP addresses; each list is treated as a separate PCP server.	[RFC7291]
159	OPTION_V4_PORTPARAMS	4	This option is used to configure a set of ports bound to a shared IPv4 address.	[RFC7618]
160	Unassigned		Previously assigned by [RFC7710]; known to also be used by Polycom.	[RFC7710][RFC8910]
161	OPTION_MUD_URL_V4	N (variable)	Manufacturer Usage Descriptions	[RFC8520]
162	OPTION_V4_DNR	N	Encrypted DNS Server	[RFC9463]
163-174	Unassigned			[RFC3942]
175	Etherboot (Tentatively Assigned - 2005-06-23)			
176	IP Telephone (Tentatively Assigned - 2005-06-23)			
177	Etherboot (Tentatively Assigned - 2005-06-23)			
177	PacketCable and CableHome (replaced by 122)			
178-207	Unassigned			[RFC3942]
208	PXELINUX Magic	4	magic string = F1:00:74:7E	[RFC5071][Deprecated]
209	Configuration File	N	Configuration file	[RFC5071]
210	Path Prefix	N	Path Prefix Option	[RFC5071]
211	Reboot Time	4	Reboot Time	[RFC5071]
212	OPTION_6RD	18 + N	OPTION_6RD with N/4 6rd BR addresses	[RFC5969]
213	OPTION_V4_ACCESS_DOMAIN	N	Access Network Domain Name	[RFC5986]
214-219	Unassigned			
220	Subnet Allocation Option	N	Subnet Allocation Option	[RFC6656]
221	Virtual Subnet Selection (VSS) Option			[RFC6607]
222-223	Unassigned			[RFC3942]
224-254	Reserved (Private Use)			
255	End	0	None	[RFC2132]