[db-wg] Proxy proposal large communities

On 13/11/17 21:52, Job Snijders wrote:
> On Mon, Nov 13, 2017 at 12:16 PM, Mark Prior <mrp at mrp.net> wrote:
>> On 13/11/17 21:36, Job Snijders wrote:
>>> On Mon, Nov 13, 2017 at 12:01 PM, Mark Prior <mrp at mrp.net> wrote:
>>>> In this particular case I would suggest that you do want the tool to
>>>> complain rather than ignore the new rp-attribute.
>>>
>>> Why would you break backwards compatibility?
>>>
>> It's only broken if you include a large community formatted string in
>> your policy and your tool doesn't support it. In that case I would like
>> the script to break rather than load a broken configuration to a router
>> that potentially causes chaos.
> 
> OK, but what about the tools from other people/organisations that parse your
> autnum object?
> 
> I'm not sure why you ignore the recommendation "When changing the dictionary,
> full compatibility should be maintained." without offering any
> arguments on what the
> benefits for doing so are.
> 
I am concerned about how a tool that doesn't understand them copes. If a
clause using large communities is just ignored then it might change a
restrictive export policy into an ANY without any warning. If that was
likely I would prefer it to break so I would know and could fix the
policy and/or tool.

As for breaking other people's interpretation of your policy that is
also probably a good thing for the same reason. I would be interested to
know about a use case for people parsing other people's policy objects.

Mark.