Re: [netmod] An abundant amount of IANA if types...

"Bogaert, Bart (Nokia - BE/Antwerp)" <> Fri, 06 April 2018 11:59 UTC

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From: "Bogaert, Bart (Nokia - BE/Antwerp)" <>
To: Juergen Schoenwaelder <>, Alex Campbell <>, "" <>
Thread-Topic: [netmod] An abundant amount of IANA if types...
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Date: Fri, 6 Apr 2018 11:59:53 +0000
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Subject: Re: [netmod] An abundant amount of IANA if types...
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I was not suggesting to have a feature for all identities but I would assume that there are several identities that logically belong to each other so these could be grouped.  If this would still lead to a lot of features I do not see how a deviation can help out here to reduce the number of identities as you do not have a schema node for identities so to me the only way to reduce the amount of interface types one supports is to define a YANG module importing ietf-interfaces for the base interface-type identity and defining the set of identities required but then this not really in-line with what is coming from the standardization bodies (you could re-use the same names as used in iana-if-type but this is not very nice).

Regards, Bart

-----Original Message-----
From: Juergen Schoenwaelder [] 
Sent: Friday, April 6, 2018 1:37 PM
To: Bogaert, Bart (Nokia - BE/Antwerp) <>om>; Alex Campbell <>om>;
Subject: Re: [netmod] An abundant amount of IANA if types...

On Fri, Apr 06, 2018 at 10:51:48AM +0200, Ladislav Lhotka wrote:
> Juergen Schoenwaelder <> writes:
> > If we would have a mechanism to deviate an identityref to a subset 
> > of identity values supported by an implementation, we would have 
> > solved a more generic problem. Yes, the IANA list could be 'nicer' 
> > but it will never be 'nice'.
> Three mechanisms can be used for this:
> - splitting the identities into separate modules

Whatever module organization you come up with, it won't work for all implementations. 

> - using features

Making every identity a feature will turn the feature system upside down. This is similar to making every leaf a feature.

> - using deviations (even though vendors frown on them)

If my implementation only supports A and B and C, then a deviation may state exactly that and the problem is solved. Hoping that my specific combination of A and B and C matches a set of modules or some set of features is in my view an illusion.

Vendors not shipping proper deviations are essentially telling their customers that they have not yet understood model driven management.
We need to change the mindset here instead of polluting our data models with hundreds or thousands of fine grained 'features'.


Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
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