RFC 3024 Reverse Tunneling for Mobile IP, revised January 2001 Table of Contents 1. Introduction ................................................... 3 1.1. Terminology .................................................. 4 1.2. Assumptions .................................................. 4 1.3. Justification ................................................ 5 2. Overview ....................................................... 5 3. New Packet Formats ............................................. 6 3.1. Mobility Agent Advertisement Extension ....................... 6 3.2. Registration Request ......................................... 6 3.3. Encapsulating Delivery Style Extension ....................... 7 3.4. New Registration Reply Codes ................................. 8 4. Changes in Protocol Behavior ................................... 9 4.1. Mobile Node Considerations ................................... 9 4.1.1. Sending Registration Requests to the Foreign Agent ......... 9 4.1.2. Receiving Registration Replies from the Foreign Agent ...... 10 4.2. Foreign Agent Considerations ................................. 10 4.2.1. Receiving Registration Requests from the Mobile Node ....... 11 4.2.2. Relaying Registration Requests to the Home Agent ........... 11 4.3. Home Agent Considerations .................................... 11 4.3.1. Receiving Registration Requests from the Foreign Agent ..... 12 4.3.2. Sending Registration Replies to the Foreign Agent .......... 12 5. Mobile Node to Foreign Agent Delivery Styles ................... 13 5.1. Direct Delivery Style ........................................ 13 5.1.1. Packet Processing .......................................... 13 5.1.2. Packet Header Format and Fields ............................ 13 5.2. Encapsulating Delivery Style ................................. 14 5.2.1 Packet Processing ........................................... 14 5.2.2. Packet Header Format and Fields ............................ 15 5.3. Support for Broadcast and Multicast Datagrams ................ 16 5.4. Selective Reverse Tunneling .................................. 16 6. Security Considerations ........................................ 17 6.1. Reverse-tunnel Hijacking and Denial-of-Service Attacks ....... 17 6.2. Ingress Filtering ............................................ 18 6.3. Reverse Tunneling for Disparate Address Spaces ............... 18 7. IANA Considerations ............................................ 18 8. Acknowledgements ............................................... 18 References ........................................................ 19 Editor and Chair Addresses ........................................ 20 Appendix A: Disparate Address Space Support ....................... 21 A.1. Scope of the Reverse Tunneling Solution ................... 21 A.2. Terminating Forward Tunnels at the Foreign Agent .......... 24 A.3. Initiating Reverse Tunnels at the Foreign Agent ........... 26 A.4. Limited Private Address Scenario .......................... 26 Appendix B: Changes from RFC 2344 .................................. 29 Full Copyright Statement .......................................... 30 Montenegro Standards Track