--- 1/draft-ietf-dhc-options-1533update-04.txt 2006-02-04 23:05:03.000000000 +0100 +++ 2/draft-ietf-dhc-options-1533update-05.txt 2006-02-04 23:05:03.000000000 +0100 @@ -1,20 +1,20 @@ Network Working Group S. Alexander INTERNET DRAFT Silicon Graphics, Inc. -Obsoletes: draft-ietf-dhc-options-1533update-03.txt R. Droms +Obsoletes: draft-ietf-dhc-options-1533update-04.txt R. Droms Bucknell University - May 1996 - Expires November 1996 + November 1996 + Expires May 1997 DHCP Options and BOOTP Vendor Extensions - + Status of this memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any @@ -40,40 +40,40 @@ options will be specified in separate RFCs. The current list of valid options is also available in ftp://ftp.isi.edu/in- notes/iana/assignments [22]. All of the vendor information extensions defined in RFC 1497 [2] may be used as DHCP options. The definitions given in RFC 1497 are included in this document, which supersedes RFC 1497. All of the DHCP options defined in this document, except for those specific to DHCP as defined in section 9, may be used as BOOTP vendor information -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 extensions. Table of Contents 1. Introduction .............................................. 2 2. BOOTP Extension/DHCP Option Field Format .................. 4 3. RFC 1497 Vendor Extensions ................................ 5 4. IP Layer Parameters per Host .............................. 12 5. IP Layer Parameters per Interface ........................ 15 6. Link Layer Parameters per Interface ....................... 19 7. TCP Parameters ............................................ 20 8. Application and Service Parameters ........................ 21 9. DHCP Extensions ........................................... 29 - 10. Defining new extensions ................................... 36 - 11. Acknowledgements .......................................... 36 - 12. References ................................................ 37 - 13. Security Considerations ................................... 38 - 14. Authors' Addresses ........................................ 38 + 10. Defining new extensions ................................... 35 + 11. Acknowledgements .......................................... 35 + 12. References ................................................ 36 + 13. Security Considerations ................................... 37 + 14. Authors' Addresses ........................................ 37 1. Introduction This document specifies options for use with both the Dynamic Host Configuration Protocol and the Bootstrap Protocol. The full description of DHCP packet formats may be found in the DHCP specification document [1], and the full description of BOOTP packet formats may be found in the BOOTP specification document [3]. This document defines the format of information in the last field of DHCP @@ -91,31 +91,30 @@ DHCP and BOOTP. Section 9 defines options used only in DHCP. References further describing most of the options defined in sections 2-6 can be found in section 12. The use of the options defined in section 9 is described in the DHCP specification [1]. Information on registering new options is contained in section 10. This document updates the definition of DHCP/BOOTP options that -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 appears in RFC1533. The classing mechanism has been extended to - include vendor classes and user classes as described in section 8.4, - 9.13 and 9.15. The new procedure for defining new DHCP/BOOTP options - in described in section 10. Several new options, including NIS+ - domain and servers, Mobile IP home agent, SMTP server, TFTP server - and Bootfile server, have been added. Text giving definitions used - throughout the document has been added in section 1.1. Text - emphasizing the need for uniqueness of client-identifiers has been - added to section 9.14. + include vendor classes as described in section 8.4 and 9.13. The new + procedure for defining new DHCP/BOOTP options in described in section + 10. Several new options, including NIS+ domain and servers, Mobile + IP home agent, SMTP server, TFTP server and Bootfile server, have + been added. Text giving definitions used throughout the document has + been added in section 1.1. Text emphasizing the need for uniqueness + of client-identifiers has been added to section 9.14. 1.1 Requirements Throughout this document, the words that are used to define the significance of particular requirements are capitalized. These words are: o "MUST" This word or the adjective "REQUIRED" means that the @@ -142,23 +141,23 @@ described with this label. o "MAY" This word or the adjective "OPTIONAL" means that this item is truly optional. One vendor may choose to include the item because a particular marketplace requires it or because it enhances the product, for example; another vendor may omit the same item. -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 -1. Terminology +1.2 Terminology This document uses the following terms: o "DHCP client" A DHCP client or "client" is an Internet host using DHCP to obtain configuration parameters such as a network address. o "DHCP server" @@ -193,21 +192,21 @@ Any options defined subsequent to this document MUST contain a length octet even if the length is fixed or zero. All multi-octet quantities are in network byte-order. When used with BOOTP, the first four octets of the vendor information field have been assigned to the "magic cookie" (as suggested in RFC 951). This field identifies the mode in which the succeeding data is to be interpreted. The value of the magic cookie is the 4 octet -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 dotted decimal 99.130.83.99 (or hexadecimal number 63.82.53.63) in network byte order. All of the "vendor extensions" defined in RFC 1497 are also DHCP options. Option codes 128 to 254 (decimal) are reserved for site-specific options. @@ -233,21 +232,21 @@ The pad option can be used to cause subsequent fields to align on word boundaries. The code for the pad option is 0, and its length is 1 octet. Code +-----+ | 0 | +-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.2. End Option The end option marks the end of valid information in the vendor field. Subsequent octets should be filled with pad options. The code for the end option is 255, and its length is 1 octet. Code +-----+ @@ -266,29 +265,32 @@ Code Len Subnet Mask +-----+-----+-----+-----+-----+-----+ | 1 | 4 | m1 | m2 | m3 | m4 | +-----+-----+-----+-----+-----+-----+ 3.4. Time Offset The time offset field specifies the offset of the client's subnet in seconds from Coordinated Universal Time (UTC). The offset is - expressed as a two's complement 32-bit integer. The code for the time - offset option is 2, and its length is 4 octets. + expressed as a two's complement 32-bit integer. A positive offset + indicates a location east of the zero meridian and a negative offset + indicates a location west of the zero meridian. + + The code for the time offset option is 2, and its length is 4 octets. Code Len Time Offset +-----+-----+-----+-----+-----+-----+ | 2 | 4 | n1 | n2 | n3 | n4 | +-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.5. Router Option The router option specifies a list of IP addresses for routers on the client's subnet. Routers SHOULD be listed in order of preference. The code for the router option is 3. The minimum length for the router option is 4 octets, and the length MUST always be a multiple of 4. @@ -320,21 +322,21 @@ The code for the name server option is 5. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 5 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.8. Domain Name Server Option The domain name server option specifies a list of Domain Name System (STD 13, RFC 1035 [8]) name servers available to the client. Servers SHOULD be listed in order of preference. The code for the domain name server option is 6. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. @@ -365,21 +367,21 @@ of preference. The code for the log server option is 8. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 8 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.11. LPR Server Option The LPR server option specifies a list of RFC 1179 [10] line printer servers available to the client. Servers SHOULD be listed in order of preference. The code for the LPR server option is 9. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. @@ -410,21 +412,21 @@ of preference. The code for this option is 11. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 11 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.14. Host Name Option This option specifies the name of the client. The name may or may not be qualified with the local domain name (see section 3.17 for the preferred way to retrieve the domain name). See RFC 1035 for character set restrictions. The code for this option is 12, and its minimum length is 1. @@ -453,21 +455,21 @@ path is formatted as a character string consisting of characters from the NVT ASCII character set. The code for this option is 14. Its minimum length is 1. Code Len Dump File Pathname +-----+-----+-----+-----+-----+-----+--- | 14 | n | n1 | n2 | n3 | n4 | ... +-----+-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.17. Domain Name This option specifies the domain name that client should use when resolving hostnames via the Domain Name System. The code for this option is 15. Its minimum length is 1. Code Len Domain Name +-----+-----+-----+-----+-----+-----+-- @@ -491,21 +493,21 @@ disk. The path is formatted as a character string consisting of characters from the NVT ASCII character set. The code for this option is 17. Its minimum length is 1. Code Len Root Disk Pathname +-----+-----+-----+-----+-----+-----+--- | 17 | n | n1 | n2 | n3 | n4 | ... +-----+-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 3.20. Extensions Path A string to specify a file, retrievable via TFTP, which contains information which can be interpreted in the same way as the 64-octet vendor-extension field within the BOOTP response, with the following exceptions: - the length of the file is unconstrained; - all references to Tag 18 (i.e., instances of the @@ -530,21 +532,21 @@ layer for packet forwarding. A value of 0 means disable IP forwarding, and a value of 1 means enable IP forwarding. The code for this option is 19, and its length is 1. Code Len Value +-----+-----+-----+ | 19 | 1 | 0/1 | +-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 4.2. Non-Local Source Routing Enable/Disable Option This option specifies whether the client should configure its IP layer to allow forwarding of datagrams with non-local source routes (see Section 3.3.5 of [4] for a discussion of this topic). A value of 0 means disallow forwarding of such datagrams, and a value of 1 means allow forwarding. The code for this option is 20, and its length is 1. @@ -570,21 +572,21 @@ Code Len Address 1 Mask 1 +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | 21 | n | a1 | a2 | a3 | a4 | m1 | m2 | m3 | m4 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ Address 2 Mask 2 +-----+-----+-----+-----+-----+-----+-----+-----+--- | a1 | a2 | a3 | a4 | m1 | m2 | m3 | m4 | ... +-----+-----+-----+-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 4.4. Maximum Datagram Reassembly Size This option specifies the maximum size datagram that the client should be prepared to reassemble. The size is specified as a 16-bit unsigned integer. The minimum value legal value is 576. The code for this option is 22, and its length is 2. Code Len Size @@ -611,21 +613,21 @@ MTU values discovered by the mechanism defined in RFC 1191 [12]. The timeout is specified as a 32-bit unsigned integer. The code for this option is 24, and its length is 4. Code Len Timeout +-----+-----+-----+-----+-----+-----+ | 24 | 4 | t1 | t2 | t3 | t4 | +-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 4.7. Path MTU Plateau Table Option This option specifies a table of MTU sizes to use when performing Path MTU Discovery as defined in RFC 1191. The table is formatted as a list of 16-bit unsigned integers, ordered from smallest to largest. The minimum MTU value cannot be smaller than 68. The code for this option is 25. Its minimum length is 2, and the length MUST be a multiple of 2. @@ -648,21 +650,21 @@ specified as a 16-bit unsigned integer. The minimum legal value for the MTU is 68. The code for this option is 26, and its length is 2. Code Len MTU +-----+-----+-----+-----+ | 26 | 2 | m1 | m2 | +-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 5.2. All Subnets are Local Option This option specifies whether or not the client may assume that all subnets of the IP network to which the client is connected use the same MTU as the subnet of that network to which the client is directly connected. A value of 1 indicates that all subnets share the same MTU. A value of 0 means that the client should assume that some subnets of the directly connected network may have smaller MTUs. @@ -693,21 +695,21 @@ should not perform mask discovery. A value of 1 means that the client should perform mask discovery. The code for this option is 29, and its length is 1. Code Len Value +-----+-----+-----+ | 29 | 1 | 0/1 | +-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 5.5. Mask Supplier Option This option specifies whether or not the client should respond to subnet mask requests using ICMP. A value of 0 indicates that the client should not respond. A value of 1 means that the client should respond. The code for this option is 30, and its length is 1. @@ -736,21 +738,21 @@ This option specifies the address to which the client should transmit router solicitation requests. The code for this option is 32, and its length is 4. Code Len Address +-----+-----+-----+-----+-----+-----+ | 32 | 4 | a1 | a2 | a3 | a4 | +-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 5.8. Static Route Option This option specifies a list of static routes that the client should install in its routing cache. If multiple routes to the same destination are specified, they are listed in descending order of priority. The routes consist of a list of IP address pairs. The first address is the destination address, and the second address is the router for @@ -764,21 +766,21 @@ Code Len Destination 1 Router 1 +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | 33 | n | d1 | d2 | d3 | d4 | r1 | r2 | r3 | r4 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ Destination 2 Router 2 +-----+-----+-----+-----+-----+-----+-----+-----+--- | d1 | d2 | d3 | d4 | r1 | r2 | r3 | r4 | ... +-----+-----+-----+-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 6. Link Layer Parameters per Interface This section lists the options that affect the operation of the data link layer on a per-interface basis. 6.1. Trailer Encapsulation Option This option specifies whether or not the client should negotiate the use of trailers (RFC 893 [14]) when using the ARP protocol. A value @@ -812,21 +814,21 @@ client should use RFC 894 encapsulation. A value of 1 means that the client should use RFC 1042 encapsulation. The code for this option is 36, and its length is 1. Code Len Value +-----+-----+-----+ | 36 | 1 | 0/1 | +-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 7. TCP Parameters This section lists the options that affect the operation of the TCP layer on a per-interface basis. 7.1. TCP Default TTL Option This option specifies the default TTL that the client should use when sending TCP segments. The value is represented as an 8-bit unsigned @@ -862,21 +864,21 @@ should not be sent. A value of 1 indicates that a garbage octet should be sent. The code for this option is 39, and its length is 1. Code Len Value +-----+-----+-----+ | 39 | 1 | 0/1 | +-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8. Application and Service Parameters This section details some miscellaneous options used to configure miscellaneous applications and services. 8.1. Network Information Service Domain Option This option specifies the name of the client's NIS [17] domain. The domain is formatted as a character string consisting of characters @@ -910,21 +912,21 @@ of preference. The code for this option is 42. Its minimum length is 4, and the length MUST be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 42 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.4. Vendor Specific Information This option is used by clients and servers to exchange vendor- specific information. The information is an opaque object of n octets, presumably interpreted by vendor-specific code on the clients and servers. The definition of this information is vendor specific. The vendor is indicated in the vendor class identifier option. Servers not equipped to interpret the vendor-specific information sent by a client MUST ignore it (although it may be reported). @@ -961,21 +963,21 @@ +-----+-----+-----+-----+--- When encapsulated vendor-specific extensions are used, the information bytes 1-n have the following format: Code Len Data item Code Len Data item Code +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | T1 | n | d1 | d2 | ... | T2 | n | D1 | D2 | ... | ... | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.5. NetBIOS over TCP/IP Name Server Option The NetBIOS name server (NBNS) option specifies a list of RFC 1001/1002 [19] [20] NBNS name servers listed in order of preference. The code for this option is 44. The minimum length of the option is 4 octets, and the length must always be a multiple of 4. Code Len Address 1 Address 2 @@ -1005,21 +1007,21 @@ Value Node Type ----- --------- 0x1 B-node 0x2 P-node 0x4 M-node 0x8 H-node In the above chart, the notation '0x' indicates a number in base-16 (hexadecimal). -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 The code for this option is 46. The length of this option is always 1. Code Len Node Type +-----+-----+-----------+ | 46 | 1 | see above | +-----+-----+-----------+ 8.8. NetBIOS over TCP/IP Scope Option @@ -1043,21 +1045,21 @@ preference. The code for this option is 48. The minimum length of this option is 4 octets, and the length MUST be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+--- | 48 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.10. X Window System Display Manager Option This option specifies a list of IP addresses of systems that are running the X Window System Display Manager and are available to the client. Addresses SHOULD be listed in order of preference. The code for the this option is 49. The minimum length of this option @@ -1089,21 +1091,21 @@ preference. The code for this option is 65. Its minimum length is 4, and the length MUST be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 65 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.13. Mobile IP Home Agent option This option specifies a list of IP addresses indicating mobile IP home agents available to the client. Agents SHOULD be listed in order of preference. The code for this option is 68. Its minimum length is 0 (indicating no home agents are available) and the length MUST be a multiple of 4. It is expected that the usual length will be four octets, containing @@ -1135,21 +1137,21 @@ The code for the POP3 server option is 70. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 70 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.16. Network News Transport Protocol (NNTP) Server Option The NNTP server option specifies a list of NNTP available to the client. Servers SHOULD be listed in order of preference. The code for the NNTP server option is 71. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. @@ -1179,21 +1181,21 @@ The code for the Finger server option is 73. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 73 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 8.19. Default Internet Relay Chat (IRC) Server Option The IRC server option specifies a list of IRC available to the client. Servers SHOULD be listed in order of preference. The code for the IRC server option is 74. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. @@ -1225,21 +1227,21 @@ The code for the StreetTalk Directory Assistance server option is 76. The minimum length for this option is 4 octets, and the length MUST always be a multiple of 4. Code Len Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | 76 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 9. DHCP Extensions This section details the options that are specific to DHCP. 9.1. Requested IP Address This option is used in a client request (DHCPDISCOVER) to allow the client to request that a particular IP address be assigned. @@ -1271,21 +1273,21 @@ This option is used to indicate that the DHCP 'sname' or 'file' fields are being overloaded by using them to carry DHCP options. A DHCP server inserts this option if the returned parameters will exceed the usual space allotted for options. If this option is present, the client interprets the specified additional fields after it concludes interpretation of the standard option fields. -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 The code for this option is 52, and its length is 1. Legal values for this option are: Value Meaning ----- -------- 1 the 'file' field is used to hold options 2 the 'sname' field is used to hold options 3 both fields are used to hold options @@ -1311,21 +1313,21 @@ This option is used to identify a bootfile when the 'file' field in the DHCP header has been used for DHCP options. The code for this option is 67, and its minimum length is 1. Code Len Bootfile name +-----+-----+-----+-----+-----+--- | 67 | n | c1 | c2 | c3 | ... +-----+-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 9.6. DHCP Message Type This option is used to convey the type of the DHCP message. The code for this option is 53, and its length is 1. Legal values for this option are: Value Message Type ----- ------------ 1 DHCPDISCOVER @@ -1353,21 +1355,21 @@ The identifier is the IP address of the selected server. The code for this option is 54, and its length is 4. Code Len Address +-----+-----+-----+-----+-----+-----+ | 54 | 4 | a1 | a2 | a3 | a4 | +-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 9.8. Parameter Request List This option is used by a DHCP client to request values for specified configuration parameters. The list of requested parameters is specified as n octets, where each octet is a valid DHCP option code as defined in this document. The client MAY list the options in order of preference. The DHCP server is not required to return the options in the requested order, @@ -1390,21 +1392,21 @@ octets of NVT ASCII text, which the client may display on an available output device. The code for this option is 56 and its minimum length is 1. Code Len Text +-----+-----+-----+-----+--- | 56 | n | c1 | c2 | ... +-----+-----+-----+-----+--- -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 9.10. Maximum DHCP Message Size This option specifies the maximum length DHCP message that it is willing to accept. The length is specified as an unsigned 16-bit integer. A client may use the maximum DHCP message size option in DHCPDISCOVER or DHCPREQUEST messages, but should not use the option in DHCPDECLINE messages. The code for this option is 57, and its length is 2. The minimum @@ -1438,21 +1440,21 @@ The value is in units of seconds, and is specified as a 32-bit unsigned integer. The code for this option is 59, and its length is 4. Code Len T2 Interval +-----+-----+-----+-----+-----+-----+ | 59 | 4 | t1 | t2 | t3 | t4 | +-----+-----+-----+-----+-----+-----+ -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 9.13. Vendor class identifier This option is used by DHCP clients to optionally identify the vendor type and configuration of a DHCP client. The information is a string of n octets, interpreted by servers. Vendors may choose to define specific vendor class identifiers to convey particular configuration or other identification information about a client. For example, the identifier may encode the client's hardware configuration. Servers not equipped to interpret the class-specific information sent by a @@ -1483,63 +1485,29 @@ hardware type of 0 (zero) should be used when the value field contains an identifier other than a hardware address (e.g. a fully qualified domain name). For correct identification of clients, each client's client- identifier MUST be unique among the client-identifiers used on the subnet to which the client is attached. Vendors and system administrators are responsible for choosing client-identifiers that meet this requirement for uniqueness. -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 The code for this option is 61, and its minimum length is 2. Code Len Type Client-Identifier +-----+-----+-----+-----+-----+--- | 61 | n | t1 | i1 | i2 | ... +-----+-----+-----+-----+-----+--- -9.15. User Class Information - - This option is used by a DHCP client to optionally identify the type - or category of user or applications it represents. The information - contained in this option is an NVT ASCII text object that represents - the user class of which the client is a member. - - DHCP administrators may define specific user class identifiers to - convey information about a client's software configuration or about - its user's preferences. For example, an identifier may specify that - a particular DHCP client is a member of the class "accounting - auditors", which have special service needs such as a particular - database server. - - Servers not equipped to interpret any of user classes specified by a - client MUST ignore it (although it may be reported). Otherwise, - servers SHOULD respond with the set of options corresponding to the - user class specified by the client. Further, if the server responds, - it MUST return this option to the client. - - Clients which do not receive information for the user class requested - SHOULD make an attempt to operate without it, although they may do so - (and may announce they are doing so) in a degraded mode. - - The code for this option is 77. The minimum length for this option - is two. - - Code Len text1 - +-----+-----+-----+-----+----- - | 77 | N | c1 | c2 | ... - +-----+-----+-----+-----+----- - -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - 10. Defining new extensions The author of a new DHCP option will follow these steps to obtain acceptance of the option as a part of the DHCP Internet Standard: 1. The author devises the new option. 2. The author requests a number for the new option from IANA by contacting: Internet Assigned Numbers Authority (IANA) USC/Information Sciences Institute @@ -1565,30 +1533,34 @@ This procedure for defining new extensions will ensure that: * allocation of new option numbers is coordinated from a single authority, * new options are reviewed for technical correctness and appropriateness, and * documentation for new options is complete and published. 11. Acknowledgements - The authors would like to thank Philip Almquist for his feedback - on this document. The comments of the DHCP Working Group are - also gratefully acknowledged. In particular, Mike Carney and - Jon Dreyer from SunSelect suggested the current format of the - Vendor-specific Information option. + The author thanks the many (and too numerous to mention!) - RFC 1497 is based on earlier work by Philip Prindeville, with - help from Drew Perkins, Bill Croft, and Steve Deering. +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 + members of the DHC WG for their tireless and ongoing efforts in + the development of DHCP and this document. + + The efforts of J Allard, Mike Carney, Dave Lapp, Fred Lien and + John Mendonca in organizing DHCP interoperability testing + sessions are gratefully acknowledged. + + The development of this document was supported in part by grants + from the Corporation for National Research Initiatives (CNRI), + Bucknell University and Sun Microsystems. 12. References [1] Droms, R., "Dynamic Host Configuration Protocol", RFC 1531, Bucknell University, October 1993. [2] Reynolds, J., "BOOTP Vendor Information Extensions", RFC 1497, USC/Information Sciences Institute, August 1993. [3] Croft, W., and J. Gilmore, "Bootstrap Protocol", RFC 951, @@ -1611,36 +1583,35 @@ [8] Mockapetris, P., "Domain Names - Implementation and Specification", STD 13, RFC 1035, USC/Information Sciences Institute, November 1987. [9] Postel, J., "Quote of the Day Protocol", STD 23, RFC 865, USC/Information Sciences Institute, May 1983. [10] McLaughlin, L., "Line Printer Daemon Protocol", RFC 1179, The Wollongong Group, August 1990. +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 + [11] Accetta, M., "Resource Location Protocol", RFC 887, CMU, December 1983. [12] Mogul, J. and S. Deering, "Path MTU Discovery", RFC 1191, DECWRL, Stanford University, November 1990. [13] Deering, S., "ICMP Router Discovery Messages", RFC 1256, Xerox PARC, September 1991. [14] Leffler, S. and M. Karels, "Trailer Encapsulations", RFC 893, U. C. Berkeley, April 1984. [15] Hornig, C., "Standard for the Transmission of IP Datagrams over - -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - Ethernet Networks", RFC 894, Symbolics, April 1984. [16] Postel, J. and J. Reynolds, "Standard for the Transmission of IP Datagrams Over IEEE 802 Networks", RFC 1042, USC/Information Sciences Institute, February 1988. [17] Sun Microsystems, "System and Network Administration", March 1990. [18] Mills, D., "Internet Time Synchronization: The Network Time @@ -1662,20 +1633,23 @@ 13. Security Considerations Security issues are not discussed in this memo. 14. Authors' Addresses Steve Alexander Silicon Graphics, Inc. 2011 N. Shoreline Boulevard + +DRAFT DHCP Options and BOOTP Vendor Extensions November 1996 + Mailstop 510 Mountain View, CA 94043-1389 Phone: (415) 933-6172 EMail: sca@engr.sgi.com Ralph Droms Bucknell University Lewisburg, PA 17837