scalars like ifNumber and ifTableLastChange

[Bert Wijnen <[e-mail]>]

Sorry for the cross posting, but it is an issue that touches all 3
areas. To prevent further duplication of postings, I suggest that
we take this discussion further on the agentX mailing list and so
anyone who wants to follow it should subscribe to that list too.

We've seen quite a few comments about the agentX protocol not being
able to cope with "aggregate scalars" like ifMIB.
Also the new ifTableLastChange is problematic for the current agentX
design.

Now... a collegue of mine (Robert Moore from IBM RTP) brought up a good
point that shows that these kind of scalars are already problematic
in the world of SNMPv2 with view definitions specified in RFC144x
and in SNMPv2* and in USEC-draft-config-document.

What do we see:
  - one can specify a MIB-view in which ifNumber and ifTableLastChange
    are included, some rows in the ifTable are included and other rows
    in the ifTable are excluded.
  - If a manager now gets ifNumber and then walks the table, then
    it turns out that the ifNumber is in many cases not equal
    to the number of rows that thus manager can get.
  - If a manager now gets ifTableLastChange, then he may see that
    this object tells him that a change took place, but in the
    table that he retrieves he sees no changes at all.
I understand that this is not a real serious problem.... but as I
have stated before, it makes one wonder what the heck these 2
objects contribute in terms of usefull information.

Comments?
Bert