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

[Brian E Carpenter <[e-mail]>]

On 23/07/2017 03:37, Philip Homburg wrote:
>> Then you really have to answer my question: if they are not called "interface
>> identifier" what are those bits called?
> 
> So let me call them 'host part'

Hate to be picky but in RFC8200 'host' does not include 'router' and these
bits certainly exist in router addresses.

So it would have to be 'node part'. But in most cases (the only exception
being anycast) these bits may be (not must be) different in the node per
interface, so 'node' is still wrong. I just don't get why it isn't
'interface part' (with an exception for anycast). And if it's 'interface
part' I really don't see why it isn't 'interface identifier'.

Here's a thought. How would it be if the contentious sentence in 4291bis
read, in its entirety:

"Interface Identifiers are 64 bits long when used for Stateless
Address Autoconfiguration (SLAAC) [RFC4862]."

?.

Who here could not live with that?

    Brian


> 
>>> What we currently have is that requirements on IID depend on the use case.
>>
>> If they are called something else, the requirements will still depend on
>> the use case.
> 
> Basically a 'host part' doesn't have any properties. You can say it
> identifies an interface, but that is not the case if a 'host part' is 
> part of an anycast address.
> 
> So a host part has a specific length, which is of course related to the
> prefix length. And that's it.
> 
> For manual address configuration, a host part doesn't have any properties
> except that it should be unique.
> 
> For DHCP IA_NA the same applies. Though in the context of DHCP you may also
> want to talk about privacy. But that goes way beyond what rfc4291 deals
> with. 
> 
> Some host parts may be anycast addresses. But by and large whether an
> address is anycast is a local flag that needs to be set. There are no specific
> requirements for host parts that are anycast addresses.
> 
> Only when a host part happens to be used in SLAAC, we get a completely
> different story.
>