Re: [Agentx] Some confusion, while watching AgentX-Register-PDU in net-snmp 5.4

["Randy Presuhn" <randy_presuhn at mindspring.com>]

Hi -

> From: "Mark Atwood" <me at mark.atwood.name>
> To: <agentx at ietf.org>
> Sent: Friday, July 06, 2007 12:46 AM
> Subject: [Agentx] Some confusion,while watching AgentX-Register-PDU in net-snmp 5.4
...
>   { Do I want to register the whole [1-5] range of the instance row 
>     instead of just [3-5]? }

There's no great benefit to doing so.

> The AgentX-Register-PDU sent was
>   flags = 0x01 (INSTANCE_REGISTRATION, !NETWORK_BYTE_ORDER)
>   range_subid = 13
>     {shouldn't this be 14?}

I'd have expected 9, based on the text on page 24 of RFC 2257,
as well as the example on page 25, since it's using the prefix kludge.
It might be worth looking at the actual byte stream, rather than
a pretty-printed version; it's possible that the pretty-printer is
obscuring what's really happening.

...
> The AgentX-Response-PDU received was
>   flags = 0x01 (INSTANCE_REGISTRATION, !NETWORK_BYTE_ORDER)
>   oid
>     n_subid = 12   prefix = 4
>     include = 0
>     suboids = 1.8072.9999.9999.947.17.61.1.3.42.1.69
>   oid
>     n_subid = 12   prefix = 4
>     include = 1 { according to RFC2741 line 725,
>                   shouldnt this should always be zero? }

Here, yes.

>     suboids = 1.8072.9999.9999.947.17.61.5.3.42.1.69
>                                         ^^^^^
>       { shouldnt this be 1.8072.9999.9999.947.17.61.1.5.42.1.69 }
>                                                    ^^^^^

No, it should match the request, so it should be
    1.8072.9999.9999.947.17.61.1.3.42.1.69
 
> Am I correctly understanding what I want to register?
> That is, when I register a instance row,
> do I want to register just the part that has data,

Yes, though it wouldn't hurt to register the whole thing.

> or also the not-accessible index variables as well?

RFC 3416 clause 4.2.5 generation of "notWritable" error is
easier to ensure if the not-accessible indexes are included.
 
> Is the range_subid in this case supposed to be 13 or 14?

I'd say 9.  (See above)

> Is the "include" in the second oid of the response varbindlist
> supposed to be 0 or 1?

I don't know where that's coming from.  As I read RFC 2247, I'd expect
the response to look more like the request.

> Interestingly, my reading of the RFC doesnt say that these two OIDS
> should be part of the AgentX-Response-PDU at all.  Is that a bug as
> well?  It's certainly useful...

Sounds bug-like to me.  :-)

Randy