[rrg] ILNP Identifiers

[Brian E Carpenter]

On 2008-12-12 04:52, Scott Brim wrote:
> RJ Atkinson allegedly wrote:
>> So I think it is important to have very crisp definitions all around
>> (forwarding vs bridging; identity vs location, et cetera)  So I try
>> to be consistent and precise with my use of terms.  However, other
>> folks' mileage differs on some/all of these issues, as is true with
>> many other issues discussed in the Routing RG.  I think we'd all be
>> better off with some agreed upon crisp definitions for various terms,
>> but past attempts to do that in this RG have not succeeded.
> 
> Just to follow up on this part ...
> 
> What you need crisp definitions for is how things are used, in protocols
> acting on packets.  Therefore you could ask
> 
>   "Is this field in the packet an identifier or is it a locator"
> 
> but you've seen how get into discussion of whether something can be a
> locator here but not there, and so on.  It's more useful to ask
> 
>   "Is this field in the packet used for identification?  Is it used by
>   forwarding?"
> 
> You could answer "yes" and "yes" or "not in this scope".

Bingo! Whether a particular binary string has value as a locator
or not depends entirely on the scope in which it's examined.
If the flat lookup table in a bridge or switch decides which
outbound interface to use on the basis of a MAC address, then it's
being used as a locator at that particular point, even though it
may have been used as an identifier during the ARP or ND process.

   Brian