Field Name

Size (bytes)

Description

Type

1

Type: Identifies the registration message type. For a request, this field is 1.

Flags

1

Lifetime

2

Lifetime: Length of time, in seconds, that the mobile node requests from the home agent for this registration.

Home Address

4

Home Address: The home (normal) IP address of the mobile node when on its home network. Uniquely identifies the device regardless of how the request is conveyed to the home agent.

Home Agent

4

Home Agent: The IP address of the device acting as the mobile node's home agent.

Care-Of Address

4

Care-Of Address: The IP address being used by the mobile node as its care-of address.

Identification

8

Identification: A 64-bit number that uniquely identifies the Registration Request and is used to match requests to replies. It also provides protection against replay attacks; see the topic on Mobile IP security issues for more.

Extensions

Variable

Extensions: Extension fields are included here for authentication of the request. Other extensions may also be included.