Subject: [MIB-DOCTORS] RFC 4001 question

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Wed, 26 Aug 2009 09:48:50 +0200

A question from a colleague of mine (copied) raised an issue I was not
able to answer and I would appreciate some help. 

         Implementations must ensure that InetAddressType objects
         and any dependent objects (e.g., InetAddress objects) are
         consistent.  An inconsistentValue error must be generated
         if an attempt to change an InetAddressType object would,
         for example, lead to an undefined InetAddress value.  In
         particular, InetAddressType/InetAddress pairs must be
         changed together if the address type changes (e.g., from
         ipv6(2) to ipv4(1))."

         The value of an InetAddress object must always be
         consistent with the value of the associated InetAddressType
         object.  Attempts to set an InetAddress object to a value
         inconsistent with the associated InetAddressType
         must fail with an inconsistentValue error.

'InetAddressType/InetAddress pairs must be changed together if the
address type changes' sounds to me like multiple SetRequest operations
should be used with pairs of objects Type/Address part of the varbind.
What happens if the only tool the operator has at hand is a MIB browser
that does not support multiple set operations? Should we always assume
that browsers MUST support multiple set? If they do the association
between corresponding  InetAddressType/InetAddress is still the
responsibility of the operator? 

Thanks and Regards,

Dan

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From: Juergen Schoenwaelder <[email-masked]>
Date: Wed, 26 Aug 2009 10:00:02 +0200

> responsibility of the operator? 

With "multiple SetRequest" you probably mean a single SetRequest with
multiple varbinds. If that interpretation is correct, then yes a MIB
browser that can do only single varbind SetRequests might have a
problem with a compliant implementation.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1, 28759 Bremen, Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>

---

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Wed, 26 Aug 2009 10:07:14 +0200

> -----Original Message-----
> From: Juergen Schoenwaelder 

> With "multiple SetRequest" you probably mean a single 
> SetRequest with multiple varbinds.

Yes. Multiple Sets request :-)

> If that interpretation is 
> correct, then yes a MIB browser that can do only single 
> varbind SetRequests might have a problem with a compliant 
> implementation.
> 

That was my guess. 

Thanks,

Dan

---

From: "Bert (IETF) Wijnen" <[email-masked]>
Date: Wed, 26 Aug 2009 11:53:46 +0200

I would think that if the InetAddressType/InetAddress pair is part of a 
row in a read-create table, that
the browser user could do:
- set row to notInService
- change InetAddressType
- change InetAddres
- set row active

Each as a separate SNMP SET request. Not ideal, but doable.
It of course also means that the agent must support the notInService for 
this to work
(which may not always be the case... some MODULE-COMPLIANCES actually do not
require support for not_inService ... or so I thought).

Bert

Romascanu, Dan (Dan) wrote:
> _______________________________________________
> MIB-DOCTORS mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mib-doctors
>
>
>

---

From: "Biton, Shlomi (Shlomi)" <[email-masked]>
Date: Wed, 26 Aug 2009 12:44:29 +0200

Hi,
What about case where the row is static/active and some of the vardinds
can be configured as InetAddressType/InetAddress?
Thanks,
Shlomi

-----Original Message-----
From: Bert (IETF) Wijnen [mailto:[email-masked]] 
Sent: Wednesday, August 26, 2009 12:54 PM
To: Romascanu, Dan (Dan)
Cc: Juergen Schoenwaelder; [email-masked]; Biton, Shlomi (Shlomi)
Subject: Re: [MIB-DOCTORS] RFC 4001 question

I would think that if the InetAddressType/InetAddress pair is part of a
row in a read-create table, that the browser user could do:
- set row to notInService
- change InetAddressType
- change InetAddres
- set row active

Each as a separate SNMP SET request. Not ideal, but doable.
It of course also means that the agent must support the notInService for
this to work (which may not always be the case... some
MODULE-COMPLIANCES actually do not require support for not_inService ...
or so I thought).

Bert

>> multiple varbinds.
>> correct, then yes a MIB browser that can do only single varbind 
>> SetRequests might have a problem with a compliant implementation.
>>
>>     
>
> That was my guess. 
>
> Thanks,
>
> Dan
>

---

From: "Bert (IETF) Wijnen" <[email-masked]>
Date: Wed, 26 Aug 2009 15:07:31 +0200

Not sure what you mean by "static" row. That sounds as if it cannot be 
modified???
If you mean that the row is static except for the 
InetAddredssType/InetAddress, then the
same applies. If the row is not read-create (so it does not have an 
RowStatus object,
then I guess you are in trouble if all your NMS (webbrowser) can do is a 
SET for one
varBind at a time.

Bert

---

From: "David Harrington" <[email-masked]>
Date: Wed, 26 Aug 2009 10:37:15 -0400

Hi,

I think the right answer is "use a tool that supports multiple
varbinds in a message".

I don't have the time right now to look up the reference, but I think
support for multiple varbinds is required for compliance to the SNMPv3
standard. That is probably stated in RFC 3416.

dbh

> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Biton, 
> Shlomi (Shlomi)
> Sent: Wednesday, August 26, 2009 6:44 AM
> To: Bert (IETF) Wijnen; Romascanu, Dan (Dan)
> Cc: [email-masked]
> SetRequest with