Re: Mib questions

[David Perkins <[e-mail]>]

Bob,

Thanks for the reply.  Here is a followup.

On question 6, which is
>>6) If more than one[agent in the chassis] implements the chassis MIB, must all the
>>   values be "consistent"?

You said...
>Muahahahahaha.  Yes, on the basis that consistent means different but related
>as opposed to identical.

I don't quite understand this, but my question was maybe not precise enough.
How about, the following...

When multiple agents in a chassis implement the MIB...
6a) Must the value of chasNumSlot be the same for both?
6b) Must the indices for the slots in the chassSlotTable be the same for both?
    (i.e., can one implement them "dense" and the other implement them "sparse"?)
6c) Can the list of devices(values for chasSlotModuleType) as seen from the
    two different agents be different.  If there can be a difference can it
    only be for values chasSlotUnknown?
6d) Is it Ok for chasSlotModuleDescr, ...Version, ...SerialNumber to have
    different values as seen from each agent.
6e) Does this list of questions have to go on for all the objects in the
    chassis MIB?

On question 9, which is
>>9) What are some situations the it would be appropriate to use
>>   a "sparse" slot table?

You said...
>Any situation the implementor chooses.  You might choose to do that in a
>2-slot chassis or one the size of Texas.

What would be a situation where an implementor would choose?  It there are no
criteria, then I would suggest in the name of interoperability that the MIB
choose one model.

On question 10, which is
>>10) Is a "logical device" a realised hardward component which has
>>    an unchanging identity, or does it also include "personalities"
>>    that are identified by the software that is running on the
>>    "logical device". An example would be a File server, loadable
>>    RMON software, Mail server, or any other "application server".

Your answer seemed to me to say that a "logical device" could be contained
on part of a physical module, a complete physical module, on on several
physical devices. I understand that - there was a proposal, i believe,
(which is not in the MIB that arneson sent out) that showed the mapping.
I was asking another, more fundamental question, that is - what really
is a logical device?  Is a module that has a general purpose CPU
on it (i.e., a "host") count as THE "logical device", or can it be
further divied so that applications running on it count as
"logical devices". (BTW - this sort of feel like the interfaces model
question.) 

On the last question that I had, which asked how was an agent that implemented
the chassis MIB to get the values for the MIB objects, you indicated
that the "most sensible" choice was to use a backplane bus. There are
two followups here.

1) Is it OK to use a VERY simple backplane bus that can give only limited
   information such as the IDs of the physical modules and which slots
   have modules installed, then use configuration files for the other
   information such as IP address?
2) How many real live implementations are there out there that have the
   backplane and CPU support to implement the complete set of objects
   without use of configuration files? (We have got to ask this question.
   If people want the responses to be confidential, then Bob or Jeff or
   someone needs to summarize the responses.)

Thanks again,
/dave perkins