Re: Metadata over IPv6

[Brian Haley <[e-mail]>]

Hi Fred,

Thanks for the response, I do have some questions.

On 12/17/19 12:32 PM, Templin (US), Fred L wrote:
>> For embedded IPv4 addresses/prefixes, however, we would use a modified
>> IPv4-compatible encapsulation as follows:
>>
>>    fe80::ffff:a9fe:a9fe
> 
> I'm sorry; I intended to say "modified IPv4-mapped encapsulation". "IPv4-compatible"
> is deprecated by RFC 4291 and would contain all-zero's instead of 0x0000ffff in bits 64-95.
> AERO uses IPv4-mapped for embedded IPv4 addresses and all-zero's for administratively
> assigned AERO addresses.

So in my case I don't think we want to define an IPv4-mapped 
encapsulation, just a new on-link anycast address that something on the 
link will answer to, it doesn't have to be the router since there might 
not actually be one.

> Also, fe80::ffff:a9fe:a9fe can be written as fe80::ffff:169.254.169.254 - the two address
> representations are equivalent.

I wouldn't mind using the AERO format, but reading the draft you listed 
it doesn't look like fe80::ffff/96 is being reserved by IANA?  Just that 
"Relay, Server and Proxy AERO addresses are allocated from the range 
fe80::/96, and MUST be managed for uniqueness." - since we do control 
the MAC we could do this I suppose as we want this link-local on the 
proxy, but what we're doing isn't really akin to AERO (IMO).

Thanks,

-Brian