Re: [Idr] draft-dong-idr-node-target-ext-comm-05.txt - WG Adoption and IPR call (9/27 to 10/11/2022)

[Robert Raszuk <[e-mail]>]

Hi,

 It is good to know that you agree such a new type of extended community is
> needed.
>

I consider defining a new sub-type of extended community dedicated to carry
BGP Identifiers as not harmful. (Even OSPF Router ID has it's place in the
BGP ext community). That is not to say that I agree there is a need for
one. I do not.


[Jie] You are correct that the withdrawal in BGP update is self-contained.
> The NT extended community only applies to the information in MP_REACH. And
> as Jeff mentioned, BGP route update is stateful on a per-route basis. If a
> BGP node needs to send withdrawal to its peer, it will be sent regardless
> of whether the withdrawal was received in an Update containing MP_REACH or
> not. In summary I don’t see this as a problem.
>

I actually do. If we would not have the concept of implicit withdrawal in
BGP that would work, but we do.

And in fact the issue applies to any filtering in IBGP mesh.

The reason we were not hurt too much (or are not aware of being hurt) in
VPN SAFIs is that most deployments either use per VRF RD or in the case of
same RD consistently allocate RTs for each src NLRIs in case of
multihoming.

The moment you want to extend the concept of IBGP filtering to any AFI/SAFI
and turn IBGP full mesh to just provide transport for p2p information
distribution I do have serious concerns about it.

Regards,
Robert