I think I understand now.  I think this feature is to be used when you're using the hub as your internet egress point, because you don't actually have a 0.0.0.0/0 route to advertise into auto-vpn in that instance.  You just have the "baked in" default route on the MX hub from it having an internet connection.  When you have a static default to the core switch, you're advertising that into auto-vpn, and therefore you don't need the box checked and it is indeed redundant.  thanks for the replies! ... View more

I am using routed mode hubs, and the default route on each DOES point to a core switch on the LAN side. It's been like 7 months since I tested this, but if I remember correctly, I didn't need to even check the box on the spoke for them to follow my default route to the hubs, since the hubs were already advertising a default AND it was visible in the route table.  During a maintenance window, I checked the box, and then disabled 0.0.0.0/0 on the hubs from being advertised into VPN fabric, but this broke the path, so no matter what, it appears I must announce a 0.0.0.0/0 from the hubs.  From my perspective, this feature doesn't do anything at all. ... View more

I have the same question as OP, but I still don't understand.   Hub has default route pointed toward LAN, and it is advertised into auto-vpn fabric - on the spoke VPN config, what does the checkbox for "IPv4 Default Route" exactly do?  I'm already default routing from the hub, as 0.0.0.0/0 is advertised into the VPN fabric.  It would appear as if this feature does nothing, in this instance.  I couldn't get an answer to this from my SE, or support.   ... View more