Re: <draft-ietf-6man-rfc4291bis-09.txt>

[james woodyatt <[e-mail]>]

On Jul 19, 2017, at 09:57, Brian E Carpenter <[e-mail]> wrote:
> On 19/07/2017 18:22, james woodyatt wrote:
>> On Jul 19, 2017, at 01:15, Brian E Carpenter <[e-mail] <mailto:[e-mail]>> wrote:
>>> 
>>> Hmm. Let's consider a case in which the last-hop route to a given LAN has a prefix of
>>> length, say, /80. What is the name of the bit-string from bits 81 through 127 of the
>>> host address? If they aren't called the "IID" what are they called?
>> 
>> If have yet to find where RFC 4291 clearly names the part of an IPv6 address that follows a *routing* prefix apart from a *subnet* prefix. Moreover, the phrase “last-hop route to a given LAN” is not equivalent to the concept of a subnet, and such a routing prefix is not equivalent to a subnet prefix. As RFC 5942 clarifies.
> 
> Agreed, but I phrased my question in full knowledge of that. What do we call those trailing
> bits of the address? (I was reading the source of the Python 'ipaddress' module yesterday,
> and saw a comment about 'host bits', but that seems very 20th century, given that the
> IPv6 architecture refers to interfaces.)

I’ve been mentally using “address suffix” for this concept, and I find that I rarely have much need for it. I suppose if I were using on-link prefixes longer than /64, then I’d need it so I could differentiate between the 64-bit Interface ID and the shorter part of the address that follows the on-link prefix.


--james woodyatt <[e-mail] <mailto:[e-mail]>>