The Mobility Header Type field identifies the type of Mobility message. Table B-29 is an overview of the Mobility messages.
Table B-29. Mobility message types
Value | Message type | Description |
---|
0 | Binding Refresh Request | Sent by CN requesting the MN to update its binding. |
1 | Home Test Init | Sent by the MN to initiate the Return Routability Procedure and request a Home Keygen token from a CN. Sent to the CN through the tunnel via HA. |
2 | Care-of Test Init | Sent by the MN to initiate the Return Routability Procedure and request a Keygen token from a CN. Sent to the CN directly. |
3 | Home Test Message | Response to a Home Test Init message (type 1). Sent from the CN to MN. Contains a cookie and a Home Keygen token for the authorization in the Return Routability Process. Sent through the tunnel via HA. |
4 | Care-of Test Message | Response to Care-of Test Init message (type 2). Sent from CN to MN. Contains cookie and a Care-of Keygen token for the authorization in the Return Routability Procedure. Sent to the MN directly. |
5 | Binding Update | Sent by MN to notify a change of its care-of address. This message is explained in more detail later in the chapter. |
6 | Binding Ack | Sent as acknowledgement for receipt of a Binding Update message. This message is explained in more detail later in the chapter. |
7 | Binding Error | Sent by CN to signal an error related to mobility, such as an inappropriate attempt to use the Home Address destination option without an existing binding. The status field can have the following values: 1 = unkown binding for Home Address Destination option 2 = unrecognized MH type value |
8 | Fast Binding Update | Identical to binding update message, only with slightly different processing rules. |
9 | Fast Binding Ack | Sent as acknowledgement for receipt of a Fast Binding Update message. |
10 | Fast Neighbor Advertisement | Sent by mobile node to announce itself to its new access router. |
Values 8, 9, and 10 have been assigned in RFC 4068 "Fast Handovers for Mobile IPv6." Find all message and option types as well as status codes at http://www.iana.org/assignments/mobility-parameters.
Table B-30 shows the status values of the Binding Update. Values in the range of 0 to 127 indicate that the Binding Update has been accepted. Values above 128 indicate that the Binding Update has not been accepted.
Table B-30. Status values in the Binding Acknowledgement
Value | Description | Defined in |
---|
0 | Binding Update accepted | RFC 3775 |
1 | Accepted but prefix discovery necessary | RFC 3775 |
128 | Reason unspecified | RFC 3775 |
129 | Administratively prohibited | RFC 3775 |
130 | Insufficient resources | RFC 3775 |
131 | Home Registration not supported | RFC 3775 |
132 | Not home subnet | RFC 3775 |
133 | Not home agent for this mobile node | RFC 3775 |
134 | Duplicate Address Detection failed | RFC 3775 |
135 | Sequence number out of window | RFC 3775 |
136 | Expired home nonce index | RFC 3775 |
137 | Expired care-of nonce index | RFC 3775 |
138 | Expired nonces | RFC 3775 |
139 | Registration type change disallowed | RFC 3775 |
140 | Mobile Router Operation not permitted | RFC 3963 |
141 | Invalid Prefix | RFC 3963 |
142 | Not Authorized for Prefix | RFC 3963 |
143 | Forwarding Setup failed | RFC 3963 |
144 | MIPV6-ID-MISMATCH | RFC 4285 |
145 | MIPV6-MESG-ID-REQD | RFC 4285 |
146 | MIPV6-AUTH-FAIL | RFC 4285 |
Table B-31 shows an overview of the currently defined options for mobility messages.
Table B-31. Mobility options
Value Length | Name | Description | Defined in |
---|
Type 0 | Pad1 | Used to insert one padding Byte. This option has a special format; it contains only a type field, and no fields for length and data. | RFC 3775 |
Type 1 | PadN | Used to insert two or more padding Bytes. | RFC 3775 |
Type 2 Length 2 | Binding Refresh Advice | Indicates the remaining time until the MN should send a new home registration to HA. Only valid in Binding Acks sent from the HA in response to a home registration. The interval must be shorter than the lifetime value in the Binding Acknowledgement. A time unit is four seconds. | RFC 3775 |
Type 3 Length 16 | Alternate Care-of address | Contains an address to use as the care-of address for the binding rather than using the Source address of the packet as the care-of address. Only in Binding Update messages. | RFC 3775 |
Type 4 Length 4 | Nonce Indices | Has two additional fields besides the Type and Length field. The Home Nonce Index field tells the CN which nonce value to use when producing the Home Keygen Token. The Care-of Nonce field indicates the value for generating the Care-of Keygen Token. Valid only in the Binding Update message sent to a CN, and only when present together with a Binding Authorization Data option. | RFC 3775 |
Type 5 Length variable | Binding Authorization Data | Contains a cryptographic value that can be used to determine that the message in question comes from the right authority. Rules for calculating this value depend on the authorization procedure used. Must always be the last option in the MH. Only valid in Binding Update and Binding Acknowledgement. Used for the Return Routability process. In this case, the calculation of the Authenticator value is based on care-of address of MN, IPv6 address of CN, and data from the MH. | RFC 3775 |
Type 6 | Mobile Network Prefix Option | Included in the Binding Update to indicate the prefix information for the Mobile Network to the HA. | RFC 3963 |
Type 7 | Mobility Header Link-Layer Address option | Link-layer address option carried in an MH; used for Fast Handovers. | RFC 4068 |
Type 8 | MN-ID-OPTION-TYPE | Optional suboption in the MH to specify the type of identifier used to identify the MN. | RFC 4283 |
Type 9 | AUTH-OPTION-TYPE | When receiving a binding update, the HA must check the timestamp field. If it is invalid, it replies with a binding acknowledgment including this status code. | RFC 4285 |
Type 10 | MESG-ID-OPTION-TYPE | Defines the type of mobility option. | RFC 4285 |
Type 201 Length 16 | Home Address | Contains the home address of MN. Sent by MN when away from home to indicate its home address to the receiver. Carried in a Destination Options header. Must be inserted after Routing header and before Fragment, AH, or ESP header (if present). | RFC 3775 |