Hello,
If you use the default-route imported command to import the default route, you need to run the import-route command first. If you run only the default-route imported command, the default route cannot be imported. In addition, the default-route imported command is used to import only the default routes that exist in the local routing table.
And after the peer default-route-advertise command is used on a device, the device sends a default route with the local address as the next-hop address to a specified peer, regardless of whether there is a default route in the routing table.
If you want to send the default route to a specified BGP peer only when the default route exists in the local routing table, kindly use the following command:
peer xx.xx.xx.xx default-route-advertise conditional-route-match-all 0.0.0.0 0