| mip.auth.auth | Authenticator | Byte array | Authenticator. |
| mip.auth.spi | SPI | Unsigned 32-bit integer | Authentication Header Security Parameter Index. |
| mip.b | Broadcast Datagrams | Boolean | Broadcast Datagrams requested |
| mip.coa | Care of Address | IPv4 address | Care of Address. |
| mip.code | Reply Code | Unsigned 8-bit integer | Mobile IP Reply code. |
| mip.d | Co-lcated Care-of Address | Boolean | MN using Co-located Care-of address |
| mip.ext.auth.subtype | Gen Auth Ext SubType | Unsigned 8-bit integer | Mobile IP Auth Extension Sub Type. |
| mip.ext.len | Extension Length | Unsigned 16-bit integer | Mobile IP Extension Length. |
| mip.ext.type | Extension Type | Unsigned 8-bit integer | Mobile IP Extension Type. |
| mip.extension | Extension | Byte array | Extension |
| mip.flags | Flags | Unsigned 8-bit integer | |
| mip.g | GRE | Boolean | MN wants GRE encapsulation |
| mip.haaddr | Home Agent | IPv4 address | Home agent IP Address. |
| mip.homeaddr | Home Address | IPv4 address | Mobile Node's home address. |
| mip.ident | Identification | Date/Time stamp | MN Identification. |
| mip.life | Lifetime | Unsigned 16-bit integer | Mobile IP Lifetime. |
| mip.m | Minimal Encapsulation | Boolean | MN wants Minimal encapsulation |
| mip.nai | NAI | String | NAI |
| mip.s | Simultaneous Bindings | Boolean | Simultaneous Bindings Allowed |
| mip.t | Reverse Tunneling | Boolean | Reverse tunneling requested |
| mip.type | Message Type | Unsigned 8-bit integer | Mobile IP Message type. |
| mip.v | Van Jacobson | Boolean | Van Jacobson |