How accounce Network in Origin by cisco

Step1

add address to address-family bgp

add static route network to null0 with 254

Now annonce network

https://community.cisco.com/t5/switching/purpoese-of-ip-route-x-x-x-x-null-0-bgp-command/td-p/1887080
https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/19345-bgp-noad.html