On Tue, Sep 24, 2024 at 02:57:21PM +0200, Ben Cartwright-Cox via NANOG wrote:
One example is if the customer is doing ROKI ROV validation (and their upstream isn't) having a default would defeat ROV validation
Ben, Perhaps I am misunderstanding you ... but I am not sure default routes 'defeat' ROV. ROV is useful in multi-homed scenarios (simple example: ISP has 1 upstream and is connected to 2 IXPs). Using ROV will mean that in the face of the ISP having multiple routes to a given destination, the legit route is more likely to be selected as best path. If there is no route via any of the peers at the IXPs, the packet goes to transit: nothing is lost/defeated because there was no alternative route anyway. The alternative would've been to drop the packet of the floor, whereas using the default route is a last ditch attempt to deliver. I think that having a default route does not take away any value from applying ROV on EBGP (peering) sessions. Kind regards, Job