Hi, On 2008/12/12, at 11:52, Julien Laganier wrote:
On Thursday 11 December 2008, Ryuji Wakikawa wrote:Actually, it's not only 3 round trip and is not optimization problem.. This is a big issue of DHCP-PD. Let me explain the issue clearly. According to the NEMO-DHCP-PD spec, before receiving a prefix, a mobile router must create a tunnel with its HA.There would be no issue at all with the MR being configured as both a DHCP client and relay, and the HA as a DHCP server: the DHCP messages would be unicasted bewteen MR and HA without tunneling.
Do you then suggest to do the prefix delegation procedure before the NEMO registration? I think this raises multiple issues.
First the DHCP relay would use the CoA as source address of the message, but the DHCPv6 server may need to know the MR's HoA if it is configured with static assignment of the MNP.
Furthermore, once the MR registers its allocated MNP to the HA, the HA cannot verify that the MNP that is in the BU was the one that the DHCP server allocated to that MR. To do so, the DHCP server would need to give the HoA/MNP pair to the HA, so that it can perform a check at registration.
By using the MR-HA tunnel, the relay message is sent using the HoA. Also, the use of an IPsec tunnel will secure the message exchange between the MR and the HA.
As for the issues raised by Ryuji, I'll reply in another mail. Cheers, romain _______________________________________________ MEXT mailing list MEXT at ietf.org https://www.ietf.org/mailman/listinfo/mext