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,

> A has a properties change for the route

That is why I said in the same RD case (not recommended anyway) the change
must be symmetric to all VRFs sourcing such route.

Kind regards,
Robert.


On Fri, Oct 21, 2022 at 10:13 PM Jeffrey Haas <[e-mail]> wrote:

>
>
> On Oct 21, 2022, at 12:27 PM, Robert Raszuk <[e-mail]> wrote:
>
>
>
>> Perhaps Robert will share whose implementation is intentionally broken in
>> this fashion to help shortcut that process.
>
>
> I do not consider implementation to be broken the moment IDR decides to
> use BGP as point to point configuration protocol and forces it to filter
> BGP UPDATES from arbitrary AFI/SAFI when propagating towards IBGP peers.
>
> For current SAFIs with unique RDs and RT based filtering nothing is broken.
>
>
> A peers with B with RT-C and L3VPN.
> B advertises to A an RT-C route that attracts route-target:100:100
>
> A theoretically filters L3VPN routes at the update-send portion of the
> process by dropping updates containing no matching RT-C extended
> communities of interest.
>
> A advertises L3VPN route RD:prefix to B with route-target:100:100 and
> route-target:200:200.  This matches received RT-C for route-target:100:100
> from B and is thus transmitted.
>
> A has a properties change for the route and needs to advertise L3VPN route
> RD:prefix to B with only route-target:200:200.
> There is no matching received RT-C route from B with this route-target.
>
> If the route is filtered, B now has stale state.
>
> If A doesn't generate a withdraw for this route, B now has stale state.
>
> Q.E.D.
>
> -- Jeff
>
>