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Internet Engineering Task Force                               C. Perkins
INTERNET DRAFT                                                       IBM
                                                        22 November 1995


                           Options for DHCPv6
                      draft-ietf-dhc-v6opts-00.txt


Status of This Memo

   This document is a submission to the Dynamic Host Configuration
   Working Group of the Internet Engineering Task Force (IETF). Comments
   should be submitted to the dhcp-v6@bucknell.edu mailing list.

   Distribution of this memo is unlimited.

   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 time.  It is inappropriate to use Internet- Drafts as reference
   material or to cite them other than as ``work in progress.''

   To learn the current status of any Internet-Draft, please check the
   ``1id-abstracts.txt'' listing contained in the Internet- Drafts
   Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
   munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
   ftp.isi.edu (US West Coast).


Abstract

   The Dynamic Host Configuration Protocol for IPv6 [2] (DHCPv6)
   provides a framework for passing configuration information to hosts
   on a TCP/IP network.  Configuration parameters and other control
   information are carried in tagged data items that are stored in the
   "options" field of the DHCPv6 message.  The data items themselves are
   also called "options."

   This document specifies the current set of DHCPv6 options.  This
   document will be periodically updated as new options are defined.
   Each superseding document will include the entire current list of
   valid options.







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                                Contents



Status of This Memo                                                    i

Abstract                                                               i

 1. Introduction                                                       1

 2. DHCPv6 Option Field Format                                         1

 3. Option specifications                                              2
     3.1. Pad Option  . . . . . . . . . . . . . . . . . . . . . . .    2
     3.2. End Option  . . . . . . . . . . . . . . . . . . . . . . .    2
     3.3. Routing Prefix size . . . . . . . . . . . . . . . . . . .    2
     3.4. Time Offset . . . . . . . . . . . . . . . . . . . . . . .    3
     3.5. Router Option . . . . . . . . . . . . . . . . . . . . . .    3
     3.6. Domain Name Server Option . . . . . . . . . . . . . . . .    3
     3.7. Host Name Option  . . . . . . . . . . . . . . . . . . . .    4
     3.8. Resource Location Server Option . . . . . . . . . . . . .    4
     3.9. Boot File Size Option . . . . . . . . . . . . . . . . . .    4
    3.10. Domain Name . . . . . . . . . . . . . . . . . . . . . . .    4

 4. IP Layer Parameters per Host                                       5
     4.1. Maximum Datagram Reassembly Size  . . . . . . . . . . . .    5
     4.2. Default IP Time-to-live . . . . . . . . . . . . . . . . .    5
     4.3. Path MTU Aging Timeout Option . . . . . . . . . . . . . .    5

 5. IP Layer Parameters per Interface                                  6
     5.1. Interface MTU Option  . . . . . . . . . . . . . . . . . .    6
     5.2. Static Route Option . . . . . . . . . . . . . . . . . . .    6

 6. TCP Parameters                                                     7
     6.1. TCP Default TTL Option  . . . . . . . . . . . . . . . . .    7
     6.2. TCP Keepalive Interval Option . . . . . . . . . . . . . .    7

 7. Application and Service Parameters                                 8
     7.1. Network Time Protocol Servers Option  . . . . . . . . . .    8
     7.2. Vendor Specific Information . . . . . . . . . . . . . . .    8
     7.3. X Window System Font Server Option  . . . . . . . . . . .    9
     7.4. X Window System Display Manager Option  . . . . . . . . .    9

 8. DHCPv6 Extensions                                                 10
     8.1. Requested IP Address  . . . . . . . . . . . . . . . . . .   10
     8.2. Parameter Request List  . . . . . . . . . . . . . . . . .   10



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     8.3. Message . . . . . . . . . . . . . . . . . . . . . . . . .   10
     8.4. Maximum DHCPv6 Message Size . . . . . . . . . . . . . . .   11
     8.5. Class-identifier  . . . . . . . . . . . . . . . . . . . .   11
     8.6. Client-identifier . . . . . . . . . . . . . . . . . . . .   12
     8.7. Mobile Home Address Option  . . . . . . . . . . . . . . .   12

 9. Neighbor Discovery Extensions                                     13

10. Extensions                                                        13

11. Acknowledgements                                                  13

12. Security Considerations                                           13

Chair's Address                                                       15

Author's Address                                                      15


































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1. Introduction

   This document specifies options for use with the Dynamic Host
   Configuration Protocol for IP version 6, DHVPv6.  The full
   description of DHCPv6 packet formats may be found in the DHCPv6
   specification document [2].

   This document defines the format of information in the last field of
   DHCPv6 packets ('options').  The options defined within this document
   specify a generalized use of this area for giving information useful
   to a wide class of machines, operating systems and configurations.
   Sites with a single DHCPv6 server that is shared among heterogeneous
   clients may choose to define other, site- specific formats for the
   use of the 'options' field.

   Section 2 of this memo describes the formats of DHCPv6 options.

   Information on registering new options is contained in section 10.
   Although option numbers in this document correspond exactly to the
   same option numbers in the options specification for IPv4 [1], there
   is no requirement to keep numbering future options in any consistent
   manner except purely as a matter of editorial and cross-referencing
   convenience.


2. DHCPv6 Option Field Format

   DHCPv6 options have the same format as the BOOTP "vendor extensions"
   defined in RFC 1497 [9].  Options may be fixed length or variable
   length.  All options begin with a tag octet, which uniquely
   identifies the option.  Fixed-length options without data consist
   of only a tag octet.  Only options 0 and 255 are fixed length.  All
   other options are variable-length with a length octet following the
   tag octet.  The value of the length octet does not include the two
   octets specifying the tag and length.  The length octet is followed
   by "length" octets of data.  In the case of some variable-length
   options the length field is a constant but must still be specified.

   Any options defined subsequent to this document should contain a
   length octet even if the length is fixed or zero.

   All multi-octet quantities are in network byte-order.

   Option codes 128 to 254 (decimal) are reserved for site-specific
   options.

   All of the options described in this document will also have their
   default values specified, if any.



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3. Option specifications

3.1. Pad Option

   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  |
   +-----+


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
   +-----+
   | 255 |
   +-----+


3.3. Routing Prefix size

   The routing prefix size option specifies the length of the routing
   prefix, counting the number of leading 1 bits to be applied to the
   client's IPv6 address to get the routing prefix.

   If both the routing prefix size and the router option are specified
   in a DHCPv6 reply, the routing prefix size option MUST be first.

   The code for the routing size prefix option is 1, and its length is 1
   octet.

    Code   Len  Prefix Size
   +-----+-----+------+
   |  1  |  1  | size |
   +-----+-----+------+







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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 signed 32-bit integer.

   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 |
   +-----+-----+-----+-----+-----+-----+


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 16 octets, and the length MUST always be a multiple
   of 16.

    Code   Len   Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----
   |  3  |  n  |  a1 |  a2 | ... | a16 |  a1 |  a2 | ... | a16 | ...
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----


3.6. Domain Name Server Option

   The domain name server option specifies a list of Domain Name System
   (STD 13, RFC 1035 [5]) 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 16 octets, and the length MUST always be a
   multiple of 16.

    Code   Len   Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----
   |  6  |  n  |  a1 |  a2 | ... | a16 |  a1 |  a2 | ... | a16 | ...
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----








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3.7. Host Name Option

   This option specifies the name of the client.  The name may or may
   not be a fully qualified domain name (FQDN). See RFC 1035 [5] for
   character set restrictions.

   The code for this option is 12, and its minimum length is 1.

    Code   Len                 Host Name
   +-----+-----+-----+-----+-----+-----+-----+-----+--
   |  12 |  n  |  h1 |  h2 |  h3 |  h4 |  h5 |  h6 |  ...
   +-----+-----+-----+-----+-----+-----+-----+-----+--


3.8. Resource Location Server Option

   This option specifies a list of Resource Location servers [12]
   available to the client.  Servers SHOULD be listed in order of
   preference.

   The code for this option is 11.  The minimum length for this option
   is 16 octets, and the length MUST always be a multiple of 16.

    Code   Len   Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----
   |  11 |  n  |  a1 |  a2 | ... | a16 |  a1 |  a2 | ... | a16 | ...
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----


3.9. Boot File Size Option

   This option specifies the length in 512-octet blocks of the default
   boot image for the client.  The file length is specified as an
   unsigned 16-bit integer.

   The code for this option is 13, and its length is 2.

    Code   Len   File Size
   +-----+-----+-----+-----+
   |  13 |  2  |  l1 |  l2 |
   +-----+-----+-----+-----+


3.10. Domain Name

   This option specifies the domain name that client should use when
   resolving hostnames via the Domain Name System.




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   The code for this option is 15.  Its minimum length is 1.

    Code   Len        Domain Name
   +-----+-----+-----+-----+-----+-----+--
   |  15 |  n  |  d1 |  d2 |  d3 |  d4 |  ...
   +-----+-----+-----+-----+-----+-----+--


4. IP Layer Parameters per Host

   This section details the options that affect the operation of the IP
   layer on a per-host basis.


4.1. 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 [3].

   The code for this option is 22, and its length is 2.

    Code   Len      Size
   +-----+-----+-----+-----+
   |  22 |  2  |  s1 |  s2 |
   +-----+-----+-----+-----+


4.2. Default IP Time-to-live

   This option specifies the default time-to-live that the client should
   use on outgoing datagrams.  The TTL is specified as an octet with a
   value between 1 and 255.

   The code for this option is 23, and its length is 1.

    Code   Len   TTL
   +-----+-----+-----+
   |  23 |  1  | ttl |
   +-----+-----+-----+


4.3. Path MTU Aging Timeout Option

   This option specifies the timeout (in seconds) to use when aging Path
   MTU values discovered by the mechanism defined in RFC 1191 [6].  The
   timeout is specified as a 32-bit unsigned integer.




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   The code for this option is 24, and its length is 4.

    Code   Len           Timeout
   +-----+-----+-----+-----+-----+-----+
   |  24 |  4  |  t1 |  t2 |  t3 |  t4 |
   +-----+-----+-----+-----+-----+-----+


5. IP Layer Parameters per Interface

   This section details the options that affect the operation of the IP
   layer on a per-interface basis.  It is expected that a client can
   issue multiple requests, one per interface, in order to configure
   interfaces with their specific parameters.


5.1. Interface MTU Option

   This option specifies the MTU to use on this interface.  The MTU is
   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 |
   +-----+-----+-----+-----+


5.2. 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
   the destination.

   The default route (0.0.0.0) is an illegal destination for a static
   route.  See section 3.5 for information about the router option.

   The code for this option is 33.  The minimum length of this option is
   32, and the length MUST be a multiple of 16.

    Code   Len         Destination 1           Router 1



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   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
   |  33 |  n  |  d1 |  d2 | ... | d16 |  r1 |  r2 | ... | r16 |
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
           Destination 2           Router 2
   +-----+-----+-----+-----+-----+-----+-----+-----+---
   |  d1 |  d2 | ... | d16 |  r1 |  r2 | ... | r16 | ...
   +-----+-----+-----+-----+-----+-----+-----+-----+---


6. TCP Parameters

   This section lists the options that affect the operation of the TCP
   layer on a per-interface basis.


6.1. 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
   integer.  The minimum value is 1.

   The code for this option is 37, and its length is 1.

    Code   Len   TTL
   +-----+-----+-----+
   |  37 |  1  |  n  |
   +-----+-----+-----+


6.2. TCP Keepalive Interval Option

   This option specifies the interval (in seconds) that the client TCP
   should wait before sending a keepalive message on a TCP connection.
   The time is specified as a 32-bit unsigned integer.  A value of zero
   indicates that the client should not generate keepalive messages on
   connections unless specifically requested by an application.

   The code for this option is 38, and its length is 4.

    Code   Len           Time
   +-----+-----+-----+-----+-----+-----+
   |  38 |  4  |  t1 |  t2 |  t3 |  t4 |
   +-----+-----+-----+-----+-----+-----+








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7. Application and Service Parameters

   This section details some miscellaneous options used to configure
   miscellaneous applications and services.


7.1. Network Time Protocol Servers Option

   This option specifies a list of IP addresses indicating NTP [4]
   servers available to the client.  Servers SHOULD be listed in order
   of preference.

   The code for this option is 42.  Its minimum length is 16, and the
   length MUST be a multiple of 16.

    Code   Len         Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+--
   |  42 |  n  |  a1 |  a2 |  a3 | ... | a16 |  a1 |  ...
   +-----+-----+-----+-----+-----+-----+-----+-----+--


7.2. 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 class-identifier option.  Servers
   not equipped to interpret the vendor-specific information sent by a
   client MUST ignore it (although it may be reported).  Clients which
   do not receive desired vendor-specific information SHOULD make an
   attempt to operate without it, although they may do so (and announce
   they are doing so) in a degraded mode.

   If a vendor potentially encodes more than one item of information
   in this option, then the vendor SHOULD encode the option using
   "Encapsulated vendor-specific options" as described below:

   The Encapsulated vendor-specific options field SHOULD be encoded as
   a sequence of type/length/value fields of identical syntax to the
   DHCPv6 options field with the following exceptions:

      -    Codes other than 0 or 255 MAY be redefined by the vendor
           within the encapsulated vendor-specific extensions field,
           but SHOULD conform to the tag-length-value syntax defined in
           section 2.





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      -    Code 255 (END), if present, signifies the end of the
           encapsulated vendor extensions, not the end of the vendor
           extensions field.  If no code 255 is present, then the end of
           the enclosing vendor-specific information field is taken as
           the end of the encapsulated vendor-specific extensions field.

   The code for this option is 43 and its minimum length is 1.

   Code   Len   Vendor-specific information
   +-----+-----+-----+-----+---
   |  43 |  n  |  i1 |  i2 | ...
   +-----+-----+-----+-----+---

   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 | ... | ... |
   +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+


7.3. X Window System Font Server Option

   This option specifies a list of X Window System [11] Font servers
   available to the client.  Servers SHOULD be listed in order of
   preference.

   The code for this option is 48.  The minimum length of this option is
   16 octets, and the length MUST be a multiple of 16.

    Code   Len         Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+---
   |  48 |  n  |  a1 |  a2 | ... | a16 |  a1 |  a2 |   ...
   +-----+-----+-----+-----+-----+-----+-----+-----+---


7.4. 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 [11] 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 is 16, and the length MUST be a multiple of 16.




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    Code   Len         Address 1               Address 2
   +-----+-----+-----+-----+-----+-----+-----+-----+---
   |  49 |  n  |  a1 |  a2 | ... | a16 |  a1 |  a2 |   ...
   +-----+-----+-----+-----+-----+-----+-----+-----+---


8. DHCPv6 Extensions

   This section details the options that are specific to DHCPv6.


8.1. Requested IP Address

   This option is used in a DHCPv6 [2] client request (DISCOVER) to
   allow the client to request that a particular IP address be assigned.

   The code for this option is 50, and its length is 16.

    Code   Len   Address
   +-----+-----+-----+-----+-----+-----+
   |  50 |  n  |  a1 |  a2 | ... | a16 |
   +-----+-----+-----+-----+-----+-----+


8.2. Parameter Request List

   This option is used by a DHCPv6 client to request values for
   specified configuration parameters.  The list of requested parameters
   is specified as n octets, where each octet is a valid DHCPv6 option
   code as defined in this document.

   The client MAY list the options in order of preference.  The DHCPv6
   server is not required to return the options in the requested order,
   but MUST try to insert the requested options in the order requested
   by the client.

   The code for this option is 55.  Its minimum length is 1.

    Code   Len   Option Codes
   +-----+-----+-----+-----+---
   |  55 |  n  |  c1 |  c2 | ...
   +-----+-----+-----+-----+---


8.3. Message

   This option is used by a DHCPv6 server to provide an error message to
   a DHCPv6 client in a CONF-RESPONSE message in the event of a failure.



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   A client may use this option in a CONF-RESPONSE message to indicate
   the why the client declined the offered parameters.  The message
   consists of n octets of NVT ASCII [8] 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 | ...
   +-----+-----+-----+-----+---


8.4. Maximum DHCPv6 Message Size

   This option specifies the maximum length DHCPv6 message that it is
   willing to accept.  The length is specified as an unsigned 16-bit
   integer.  A client may use the maximum DHCPv6 message size option
   in DISCOVER or CONF-REQUEST messages, but should not use the option
   in CONF-RESPONSE messages (see [2] for DISCOVER, CONF-REQUEST, and
   CONF-RESPONSE message formats).

   The code for this option is 57, and its length is 2.  The minimum
   legal value is 576 octets.

    Code   Len     Length
   +-----+-----+-----+-----+
   |  57 |  2  |  l1 |  l2 |
   +-----+-----+-----+-----+


8.5. Class-identifier

   This option is used by DHCPv6 clients to optionally identify the type
   and configuration of a DHCPv6 client.  The information is a string of
   n octets, interpreted by servers.  Vendors and sites may choose to
   define specific 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
   client MUST ignore it (although it may be reported).

   The code for this option is 60, and its minimum length is 1.

   Code   Len   Class-Identifier
   +-----+-----+-----+-----+---
   |  60 |  n  |  i1 |  i2 | ...
   +-----+-----+-----+-----+---



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8.6. Client-identifier

   This option is used by DHCPv6 clients to specify their unique
   identifier.  DHCPv6 servers use this value to index their database
   of address bindings.  This value is expected to be unique for all
   clients in an administrative domain.

   It is expected that this field will typically contain a hardware type
   and hardware address, but this is not required.  Current legal values
   for hardware types are defined in [10].

   The code for this option is 61, and its minimum length is 2.

   Code   Len   Type  Client-Identifier
   +-----+-----+-----+-----+-----+---
   |  61 |  n  |  t1 |  i1 |  i2 | ...
   +-----+-----+-----+-----+-----+---


8.7. Mobile Home Address Option

   When this option is present in a client request message, the DHCPv6
   server is asked to send an appropriate home address to the mobile
   host.  The DHCPv6 server, in its corresponding offering message, will
   insert the requested address into the usual place for requested IP
   addresses.  The DHCPv6 server will typically notify the mobile host
   of (one of) its home agents' addresses, as configured by the local
   administration to be associated with the address given to the mobile
   host.  That home agent's IP address is inserted in the data field of
   the mobile home address option.

   It is anticipated that the mobile-IP working group will approve one
   of the current proposals for allowing a mobile host, with its already
   known mobile home address, to dynamically discover the location of a
   home agent serving the home address.  In that case, the DHCPv6 server
   may be configured to send out mobile home addresses and expect that
   the mobile host discover the home agent's address by whichever method
   is approved by the working group.

   It is also anticipated that many installations will allow several
   home agents to serve the same mobile home addresses, for redundancy
   or load sharing.  For this reason, we have also allowed for the
   possibility that the DHCPv6 server may wish to insert multiple home
   agent addresses in the mobile home address option.

   The format of the mobile home address option is as follows:

            Code Len    Home Agent Addresses (zero or more)



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            +----+----+ - -+ - -+-----+ - --+ - -+ - -+ - -+
            | 68 | n  | a1 | a2 | ... | a16 | ...
            +----+----+ - -+ - -+-----+ - --+ - -+ - -+ - -+

   The code for the mobile home address option is 68.  The length is
   16 octets multiplied by the number of home agents supplied in the
   option, which may be zero or more.  It is expected that the usual
   length will be sixteen octets, containing a single home agent's
   address.


9. Neighbor Discovery Extensions

   This section contains option definitions for specifying parameters
   that are useful with IPv6 Neighbor Discovery [7].


10. Extensions

   Additional generic data fields may be registered by contacting:

      Internet Assigned Numbers Authority (IANA)
      USC/Information Sciences Institute
      4676 Admiralty Way
      Marina del Rey, California  90292-6695

      or by email as: iana@isi.edu

   Implementation specific use of undefined generic types (including
   those in the range 69-127) may conflict with other implementations,
   and registration is required.


11. Acknowledgements

   Quite a bit of this internet draft is copied directly from
   RFC1533 [1], written by Steve Alexander and Ralph Droms.


12. Security Considerations

   Security issues are not discussed in this memo.  However, there
   is an urgent need to define some security protocol for use with
   DHCPv6, since otherwise malicious parties could create numerous
   denial-of-service style attacks based on depleting available server
   resources or providing corrupted or infected data to unsuspecting
   clients.




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References

    [1] S. Alexander and R. Droms.  DHCP Options and BOOTP Vendor
        Extensions.  RFC 1533, October 1993.

    [2] J. Bound.  Dynamic Host Configuration Protocol for IPv6.
        draft-ietf-dhc-dhcpv6-03.txt -- work in progress, November 1995.

    [3] R. Hinden.  Internet Protocol, Version 6 (IPv6) Specification.
        draft-ietf-ipngwg-ipv6-spec-02.txt - work in progress, June
        1995.

    [4] D. Mills.  Network Time Protocol (Version 3).  RFC 1305, March
        1992.

    [5] P. Mockapetris.  DOMAIN NAMES - IMPLEMENTATION AND
        SPECIFICATION.  RFC 1035, November 1987.

    [6] J. Mogul and S. Deering.  Path MTU Discovery.  RFC 1191,
        November 1990.

    [7] T. Narten, E. Nordmark, and W. Simpson.  IPv6 Neighbor
        Discovery.  draft-ietf-ipngwg-discovery-03.txt -- work in
        progress, November 1995.

    [8] J. Postel and J. Reynolds.  Telnet Protocol Specification.  RFC
        854, May 1983.

    [9] J. Reynolds.  BOOTP Vendor Information Extensions.  RFC 1497,
        August 1993.

   [10] J. Reynolds and J. Postel.  Assigned Numbers.  RFC 1700, October
        1994.

   [11] R. Scheifler.  FYI On the X Window System.  RFC 1198, January
        1991.

   [12] J. Veizades, S. Kaplan, and E. Guttman.  Service Location
        Protocol.  draft-ietf-svrloc-protocol-07.txt - work in progress,
        October 1995.











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Chair's Addresses

   The working group can be contacted via the current chair:

          Ralph Droms
          Computer Science Department
          323 Dana Engineering
          Bucknell University
          Lewisburg, PA 17837

          Phone: (717) 524-1145
          EMail: droms@bucknell.edu


Author's Address

   Questions about this memo can be directed to:

          Charles Perkins
          Room J1-A25
          T. J. Watson Research Center
          IBM Corporation
          30 Saw Mill River Rd.
          Hawthorne, NY  10532

          Work:   +1-914-784-7350
          Fax:    +1-914-784-7007
          E-mail: perk@watson.ibm.com























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