You can not have two AutoVPN nodes (spoke or hub) directly attached to the same subnet - the dashboard wont allow you to configure this.   You can have a hub with a stub network connecting to another layer 3 device (such as a layer 3 switch) that uses a static route to the ultimate network - and redistribute that into AutoVPN. If you use this method, then you can have more than one MX advertise that same route.   However there are caveats.  If only uses one of the MXs advertising the route.  Also I don't think the failover works in all cases.   To make it really work you need to be using the hubs in VPN concentrator mode, and BGP peer to another layer 3 device, and rely on that to inject the routers into AutoVPN.     All in all - don't do it.  Just arrange for 10 minutes of downtime, and cut across to using the new units. ... View more