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 , 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) []