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MOBILE IP NUMBERS
The document "IP Mobility Support" [RFC 2002] specifies some message
types and extensibility fields.
Type Name Reference
---- -------------------------------------------- ---------
0 One-byte Padding (encoded with no Length nor Data field)
16 Mobility Agent Advertisement
19 Prefix-Lengths
24 Challenge [RFC3012]
32 Mobile-Home Authentication
33 Mobile-Foreign Authentication
34 Foreign-Home Authentication
36 Generalized Mobile IP Authentication [RFC3012]
38 Critical Vendor/Organization Specific Extension (CVSE)[RFC3115]
128 Integrated Mobility Extension [Solomon]
129 Traversal Extension [Montenegro]
130 Encapsulating Delivery Style Extension [RFC2344]
131 Mobile Node NAI [RFC2794]
132 MN-FA Challenge Extension [RFC3012]
134 Normal Vendor/Organization Specific Extension (NVSE) [RFC3115]
Message Format and Protocol Extensibility
Mobile IP defines a set of new control messages, sent with UDP [17]
using well-known port number 434. Currently, the following two
message types are defined:
1 Registration Request
3 Registration Reply
Mobile IP defines a general Extension mechanism to allow optional
information to be carried by Mobile IP control messages or by ICMP
Router Discovery messages. Each of these Extensions (with one
exception) is encoded in the following Type-Length-Value format:
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | Data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type Indicates the particular type of Extension.
Length Indicates the length (in bytes) of the data field within
this Extension. The length does NOT include the Type and
Length bytes.
Data The particular data associated with this Extension. This
field may be zero or more bytes in length. The format
and length of the data field is determined by the type
and length fields.
Extensions allow variable amounts of information to be carried within
each datagram. The end of the list of Extensions is indicated by the
total length of the IP datagram.
Two separately maintained sets of numbering spaces, from which
Extension Type values are allocated, are used in Mobile IP:
- The first set consists of those Extensions which may appear only
in Mobile IP control messages (those sent to and from UDP port
number 434). Currently, the following Types are defined for
Extensions appearing in Mobile IP control messages:
32 Mobile-Home Authentication
33 Mobile-Foreign Authentication
34 Foreign-Home Authentication
36 Generalized Mobile IP Authentication [RFC3012]
38 Critical Vendor/Organization Specific [RFC3115]
Extension (CVSE)
134 Normal Vendor/Organization Specific [RFC3115]
Extension (NVSE)
- The second set consists of those extensions which may appear only
in ICMP Router Discovery messages [4]. Currently, Mobile IP
defines the following Types for Extensions appearing in ICMP
Router Discovery messages:
0 One-byte Padding (encoded with no Length nor Data field)
16 Mobility Agent Advertisement
19 Prefix-Lengths
24 Challenge [RFC3012]
38 Critical Vendor/Organization Specific [RFC3115]
Extension (CVSE)
132 MN-FA Challenge Extension [RFC3012]
134 Normal Vendor/Organization Specific [RFC3115]
Extension (NVSE)
Due to the separation (orthogonality) of these sets, it is
conceivable that two Extensions that are defined at a later date
could have identical Type values, so long as one of the Extensions
may be used only in Mobile IP control messages and the other may be
used only in ICMP Router Discovery messages.
When an Extension numbered in either of these sets within the range 0
through 127 is encountered but not recognized, the message containing
that Extension MUST be silently discarded. When an Extension
numbered in the range 128 through 255 is encountered which is not
recognized, that particular Extension is ignored, but the rest of
the Extensions and message data MUST still be processed. The Length
field of the Extension is used to skip the Data field in searching
for the next Extension.
One-byte Padding Extension
Some IP protocol implementations insist upon padding ICMP messages
to an even number of bytes. If the ICMP length of an Agent
Advertisement is odd, this Extension MAY be included in order to make
the ICMP length even. Note that this Extension is NOT intended to
be a general-purpose Extension to be included in order to word- or
long-align the various fields of the Agent Advertisement. An Agent
Advertisement SHOULD NOT include more than one One-byte Padding
Extension and if present, this Extension SHOULD be the last Extension
in the Agent Advertisement.
Note that unlike other Extensions used in Mobile IP, the One-byte
Padding Extension is encoded as a single byte, with no "Length" nor
"Data" field present. The One-byte Padding Extension is defined as
follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Type |
+-+-+-+-+-+-+-+-+
Type 0 (One-byte Padding Extension)
Code Field
The following values are defined for use within the Code field.
Registration successful:
0 registration accepted
1 registration accepted, but simultaneous mobility
bindings unsupported
Registration denied by the foreign agent:
64 reason unspecified
65 administratively prohibited
66 insufficient resources
67 mobile node failed authentication [RFC2002,RFC3012]
68 home agent failed authentication
69 requested Lifetime too long
70 poorly formed Request
71 poorly formed Reply
72 requested encapsulation unavailable
73 requested Van Jacobson compression unavailable
74 request reverse tunnel unavailable [RFC2344]
75 reverse runnel is mandatory and 'T' bit not set [RFC2344]
76 mobile node too distant [RFC2344]
79 delivery style not supported [RFC3024]
80 home network unreachable (ICMP error received)
81 home agent host unreachable (ICMP error received)
82 home agent port unreachable (ICMP error received)
88 home agent unreachable (other ICMP error received)
89-95 unassigned
96 nonzero_homeaddr_reqd [RFC2794]
97 missing_nai [RFC2794]
98 missing_home_agent [RFC2794]
99 missing_homeaddr [RFC2794]
100 ERROR-FA-1 [RFC3115]
101 ERROR-FA-2 [RFC3115]
102-103 unassigned
104 unknown_challenge [RFC3012]
105 missing_challenge [RFC3012]
106 stale_challenge [RFC3012]
Registration denied by the home agent:
128 reason unspecified
129 administratively prohibited
130 insufficient resources
131 mobile node failed authentication
132 foreign agent failed authentication
133 registration Identification mismatch
134 poorly formed Request
135 too many simultaneous mobility bindings
136 unknown home agent address
137 request reverse tunnel unavailable [RFC2344]
138 reverse runnel is mandatory and 'T' bit not set [RFC2344]
139 requested encapsulation unavailable [RFC2344]
140 ERROR-HA-1 [RFC3115]
141 ERROR-HA-2 [RFC3115]
SPI Values for the Mobile IP Reserved SPIs
0 Reserved [RFC3012]
1 Reserved [RFC3012]
2 CHAP [RFC3012]
Generalized Authentication Extension - Subtypes
1 MN-AAA Authentication subtype [RFC3012]
PEOPLE
------
[Solomon] Jim Solomon <solomon@comm.mot.com>, December 1997.
REFERENCES
----------
[RFC2344] Montenegro, G., Edtior, "Reverse Tunneling for Mobile IP",
RFC 2344, May 1998.
[RFC2794] Calhoun, P. and C. Perkins, "Mobile IP Network Access
Identifier Extension for IPv4", RFC 2794, March 2000.
[RFC3012] C. Perkins and P. Calhoun, "Mobile IPv4 Challenge/Response
Extensions", RFC 3012, November 2000.
[RFC3024] G. Montenegro, "Reverse Tunneling for Mobile IP, revised",
RFC 3024, January 2001.
[RFC3115] Dommety, G., and K. Leung, "Mobile IP
Vendor/Organization-Specific Extensions", RFC 3115,
April 2001.
(last updated Apr 09 2001)
[]
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