[Softwires] Comments on draft-ietf-softwire-multicast-prefix-option

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Hi authors,
I’ve spent some time on reading this document and I think it is a good piece of work to define a new DHCPv6 option to carry the IPv6 prefixes.
 
Here are several comments.
 
1.       Could you please explain why the ‘DHCPv6 server supporting OPTION_V6_PREFIX64 should be configured with U_PREFIX64 and at least one ASM_PREFX64 or one SSM_PREFIX64’ in section 4? 
This statement confuses me because when the ASM mode is supported, there is no need to configure the U_PREFIX64.
 
2.       I do not really understand the following part in section 4.
When ASM_PREFIX64 and SSM_PREFIX64 are configured, the length of these prefixes must be /96.
You have mentioned in the section 3 that those prefixes are likely to be /96 not must be. Could you do me a favor to explain it more specifically?
 
3.       Would you please describe the following part in section 5 in detail?
if both SSM and ASM modes are supported
The modes above are supported by the server or the client?
 
4.       It seems that there is not a clear part that indicating which DHCPv6 message will carry the new DHCPv6 option. Do you think it is more appropriate to add a separate part to discuss this issue especially when the client is at the DHCP renew stage?
 
5.       I also find that there is a spelling mistake in the following part in section 5.
the Pv4 multicast address is inserted in the last 32 bits of the IPv4-embedded IPv6 multicast address.
        Where the second word should be IPv4.
 
Best regards,
Linhui Sun



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