1. 1 Dual Stack Support in Mobile IPv6 for Hosts and Routers OR IPv4 traversal for Mobile IPv6 ! draft-ietf-mip6-nemo-v4traversal-00 H. Soliman, G. Tsirtsis, V. Devarapalli, J. Kempf H. Levkowetz, P. Thubert, R. Wakikawa

2. 2 Objectives All goals must apply to hosts and routers (MIPv6 and NEMO). Allow MIPv6-only to be used by dual stacked MNs. (IPv4 and IPv6 capable nodes). –MIPv6 support for IPv4 CoAs –MIPv6 support for IPv4 HoA/MNP –Support for Static and Dynamic HoA/MNP allocation –NAT detection –NAT Traversal –No Route optimization support

3. 3 IPv4/v6 Scenarios MN and HA supports both IPv4 and IPv6 MIPv6-only support in MN and HA HA may be behind a NAT but reachable with a public address. Internet IPv6 IPv4 DS HAv6 NAT DS MN NAT

4. 4 Extensions to MIPv6 for tunnel setup IPv4 Home address option (present in the BU) IPv4 home address ack option (present in BA) NAT detection option (present in the BA) Protocol extensions: –Setting up IPv6 n IPv4, IPv4 n IPv6 and IPv4 n IPv4 tunnels –NAT detection and Traversal –Dynamic and static allocation of IPv4 home addresses and MNPs

5. 5 MIPv6 Solution Overview IPv4-only network: –MN sends a BU tunneled in UDP and IPv4. BU may contain an IPv4 address option. –HA detects presence of a NAT and includes the NAT detection option in the BA if a NAT were present. –MN receives the BU. If a NAT were present, the MN tunnels all traffic in UDP/IPv4. Otherwise, the traffic is tunneled in IPv4. –Tunnel is setup between the MN’s IPv4 CoA and the HA’s IPv4 address. IPv6 or Dual stack network: –Normal MIPv6 behaviour with one extension: The MN may add the IPv4 home address option to request an additional binding for the IPv4 HoA/HoP.

6. 6 Creating Bindings in MIPv6 Dual Stack HA Dual Stack MN DS-MIPv6 BU(HoAv4, HoAv6, CoAv4) HoAv4 HoAv6 CoAv4 Mobility Binding IPv6 Tunnel HAv4->CoAv4 IPv4 traffic CNv4->HoAv4 IPv6 traffic CNv6->HoAv6

7. 7 NAT Traversal It is assumed that the HA is configured with the knowledge of whether a NAT is present at the edge of its (home) site. NAT detection is done during the BU/BA exchange. The HA compares the src address in the outer header with the IPv4 address in the src address of the BU message. If the two addresses are not the same, a NAT is in the path. NAT traversal is done using UDP encapsulation. Keepalives are done by resending the BU before the NAT binding timer expires (probably less than the BCE timer).

8. 8 Comments/suggestions for next revision Possibly add another lightweight mechanism for keepalives. Add movement detection for IPv4-only networks (reference DNAv4). Clarify the security requirements for the draft and whether anything is needed in addition to RFCs 3775/3776. Add proxy ARP for HA. Allow for more than one MNP to be allocated to the MN. Find Consensus on Pascal’s comments on NAT traversal. Address Keichi’s comments for processing of IPv4 MNPs and forwarding behviour in the MR. Find consensus on the best method for transporting IPv4 CoA. Several editorials.