[Roll] DCO Invalidation triggered from ancestor node

[Rahul Arvind Jadhav <[e-mail]>]

Hello ROLL,

During the review of draft-ietf-roll-efficient-npdao-10, there was a point raised by Alvaro which we would like to bring to the WG.

The draft adds DCO msg which allows route invalidation by the common ancestor node. The DCO message is generated by the ancestor node in response to DAO with I-flag (invalidate previous route flag) set in context to the corresponding target. The I-flag is used as a mechanism so that the target is in-charge of its own invalidation. Having said that, the ancestor node has all the state information needed to generate the DCO __unilaterally__.

We would like to understand WG thoughts on "whether this unilateral invalidation from ancestor can be allowed or we should strictly let the ancestor node generate DCO in response to DAO with I-flag set."

Am not quoting pros/cons of the approaches, because this might bias the thinking and it would be nice to have different perspectives.

A diagram to aid understanding: https://github.com/roll-wg/efficient-route-invalidation/blob/master/unilateral-dco.md

Any feedback will be very useful and appreciated.

Thanks,
Rahul