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Re: [Lsr] Open issues with Dynamic Flooding

Peter Psenak <ppsenak@cisco.com> Tue, 05 March 2019 21:08 UTC

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To: tony.li@tony.li
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Cc: lsr@ietf.org
From: Peter Psenak <ppsenak@cisco.com>
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Date: Tue, 05 Mar 2019 22:08:19 +0100
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Subject: Re: [Lsr] Open issues with Dynamic Flooding
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Hi Tony,

On 05/03/2019 21:47 , tony.li@tony.li wrote:
>
>>> LS topologies can have a very large number of adjacencies as well,
>>> typically with multiple spines, so for a new spine, all of the of the
>>> links may be unnecessary.
>>
>> ok, we talked bout the balance before - adding one link at a time to
>> the FT may result in slow recovery, while adding all link is claimed
>> to be dangerous. What is the right number? I feel that the increment
>> value can be something that the implementation can choose or even make
>> configurable, so the user can decide based on the particular topology
>> and scale. We are not going to find the magic value I'm afraid.
>
>
>
> I agree that optimal is probably unknowable. The question then is what
> do we say in the document?  How about something about rate limiting?

yes, something of that nature, with possible config option.

>
>
>>> Let’s set the algorithmic parts aside.  Do you have an objection to
>>> supporting them in the signaling?
>>
>> will get complicated, especially for OSPF/OSPFv3.
>
>
> I have great confidence in you. ;-)
>
>
>> Also temporary flooding operation on LAN is tricky and sub-optimal. I
>> don't really believe it's worth the complexity.
>
>
> Ok, I’m not following this.  It seems like one system would request
> flooding and the other nodes would comply.  Where’s this tricky?

the trick is that "all" nodes would comply, where we may only need 
one/subset to do...

thanks,
Peter


>
> Tony
>
>

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