Re: draft-ietf-rtgwg-policy-model default reject-route

Agree.

Cheers,
Jeff

> On Sep 27, 2021, at 16:20, Chris Smiley <csmiley@amsl.com> wrote:
> 
> 
> Adding rfc-editor@rfc-editor.org
> 
> 
>> On Sep 27, 2021, at 11:58 AM, Acee Lindem (acee) <acee@cisco.com> wrote:
>> 
>> Hi Kris, 
>> I agree with your analysis and proposal. Do others have comment? If not,  we should remove during AUTH48 (Chris Smiley copied). 
>> Thanks,
>> Acee
>> 
>> On 9/17/21, 10:55 AM, "rtgwg on behalf of Kris Lambrechts" <rtgwg-bounces@ietf.org on behalf of kris@netedge.plus> wrote:
>> 
>>   Hi,
>> 
>>   I have been working on an implementation of
>>   ietf-routing-policy@2021-08-12.yang and
>>   ietf-bgp-policy@2021-07-11.yang and I'm struggling to implement a
>>   pattern that I think is very common among routing policies.
>> 
>>   The problem I'm seeing is with the policy-result leaf under actions.
>>   It is of type policy-result-type meaning that it can be either
>>   accept-route or reject-route with a default of reject-route. As per
>>   section 5.  Policy evaluation, all processing ends when either of
>>   these is encountered. That would mean only one statement in a policy
>>   can ever be processed. The first paragraph of section 5 suggests the
>>   presence of those actions is optional however:
>>> If the actions include either accept-route or reject-route actions, evaluation of the current policy definition stops, and no further policy statement is evaluated.
>> 
>>   In any vendor implementation I'm familiar with it is possible, and
>>   common in practice, to combine actions (i.e. set a BGP community or
>>   local-preference) from various statements which are processed in order
>>   by either implicitly or explicitly continuing on to the next
>>   statement.
>> 
>>   So my proposal here is to remove the default statement from the
>>   policy-result, which would signify an implicit continuation to the
>>   next statement. Or with the same net effect, you could add a
>>   next-statement enum to the policy-result-types to make the choice
>>   explicit.
>> 
>>   I feel like either change would make it much easier to write elegant,
>>   compact and easy-to-understand policies (and to port existing
>>   policies). Still, if this goes against your intended design, it would
>>   be good to fix any wording in the draft that implies that these
>>   actions are optional.
>> 
>>   Thank you,
>> 
>>   Kris Lambrechts
>> 
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> 