By default, a device does not generate or advertise a default route to its neighboring ISs. A default route is not advertised even if the device‘s IPv6 route table contains a default route. You can enable the device to advertise a default route to all neighboring ISs.
Note
This feature requires the presence of a default route in the IPv6 route table.You can also use a route map to configure the device to advertise a default route. The route map must be configured before you can use the route map to configure the device to advertise the default route.