Re: [netmod] 6991bis: address-with-prefix-length

Kristian Larsson <kristian@spritelink.net> Mon, 01 April 2019 20:08 UTC

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From: Kristian Larsson <kristian@spritelink.net>
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Date: Mon, 1 Apr 2019 22:08:47 +0200
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Subject: Re: [netmod] 6991bis: address-with-prefix-length
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Hello Mahesh,

On 2019-04-01 21:40, Mahesh Jethanandani wrote:
> 
>> On Apr 1, 2019, at 10:29 AM, Martin Bjorklund <mbj@tail-f.com> wrote:
>>
>> I know that this type is convenient, esp. if you use it for manual
>> input, but I wonder if it really is good practice to squeeze two
>> values into one.
> 
> Agree. The combination makes sense for CLI, but for modeling the address and prefix should be separate.

Okay, then why do we have an ip-prefix data type at all? With the same 
line of argument you apply, it should be split up.

So you're the third person bringing up CLI. I don't get this at all. I 
don't see how CLI are different from everything else. This is about data 
modeling and data modeling is about expressing the world in a data 
modeling language. It's like painting a picture but instead of a brush 
you have a schema language like YANG. What do you see? Express it. It 
doesn't matter if the purpose is a CLI, a web page or just exposing it 
via NETCONF for another system to consume.

I think address-and-prefix-length is natural. JUNOS uses this format. XR 
uses this format (for IPv6 at least). Nokia SROS uses this format.

We have written a bunch of models where the lack of this IMHO makes them 
less elegant. I'd like for there to be an IETF standard data type to 
make those models more elegant.

Kind regards,
    Kristian.