Add a network prefix that the firewall advertises to its BGP neighbors.
To add an advertised network
Navigate to NETWORK | System > Dynamic Routing > BGP.
In the Advertised Networks section, click Add Network.
In the Network (CIDR) field, enter the network prefix and prefix length in Classless Inter-Domain Routing (CIDR) notation, such as 10.0.0.0/8 or 2001:db8::/32.
Click Add.
The firewall also advertises the routes that you select in the Redistribute options in the BGP Global Settings dialog box. Advertise only network prefixes that your organization owns or is authorized to advertise.