The Southbound API is used to communicate between Controllers and network devices

A bridge group is a group of interfaces that the ASA bridges instead of routes. Bridge groups are only supported in Transparent Firewall Mode. Like any other firewall interfaces, access control between interfaces is controlled, and all of the usual firewall checks are in place. Each bridge group includes a Bridge Virtual Interface (BVI). The ASA uses the BVI IP address as the source address for packets originating from the bridge group. The BVI IP address must be on the same subnet as the bridge group member interfaces. The BVI does not support traffic on secondary networks; only traffic on the same network as the BVI IP address is supported. You can include multiple interfaces per bridge group. If you use more than 2 interfaces per bridge group, you can control communication between multiple segments on the same network, and not just between inside and outside. For example, if you have three inside segments that you do not want to communicate with each other, you can put each segment on a separate interface, and only allow them to communicate with the outside interface. Or you can customize the access rules between interfaces to allow only as much access as desired. Reference: https://www.cisco.com/c/en/us/td/docs/security/asa/asa95/configuration/general/asa-95-generalconfig/intro-fw.html Note: BVI interface is not used for management purpose. But we can add a separate Management slot/port interface that is not part of any bridge group, and that allows only management traffic to the ASA.
supported in Transparent Firewall Mode. Like any other firewall interfaces, access control between interfaces is controlled, and all of the usual firewall checks are in place.
Each bridge group includes a Bridge Virtual Interface (BVI). The ASA uses the BVI IP address as the source address for packets originating from the bridge group. The BVI IP address must be on the same subnet as the bridge group member interfaces. The BVI does not support traffic on secondary networks; only traffic on the same network as the BVI IP address is supported.
You can include multiple interfaces per bridge group. If you use more than 2 interfaces per bridge group, you can control communication between multiple segments on the same network, and not just between inside and outside. For example, if you have three inside segments that you do not want to communicate with each other, you can put each segment on a separate interface, and only allow them to communicate with the outside interface. Or you can customize the access rules between interfaces to allow only as much access as desired.
Reference:
A bridge group is a group of interfaces that the ASA bridges instead of routes. Bridge groups are only supported in Transparent Firewall Mode. Like any other firewall interfaces, access control between interfaces is controlled, and all of the usual firewall checks are in place. Each bridge group includes a Bridge Virtual Interface (BVI). The ASA uses the BVI IP address as the source address for packets originating from the bridge group. The BVI IP address must be on the same subnet as the bridge group member interfaces. The BVI does not support traffic on secondary networks; only traffic on the same network as the BVI IP address is supported. You can include multiple interfaces per bridge group. If you use more than 2 interfaces per bridge group, you can control communication between multiple segments on the same network, and not just between inside and outside. For example, if you have three inside segments that you do not want to communicate with each other, you can put each segment on a separate interface, and only allow them to communicate with the outside interface. Or you can customize the access rules between interfaces to allow only as much access as desired. Reference: https://www.cisco.com/c/en/us/td/docs/security/asa/asa95/configuration/general/asa-95-generalconfig/intro-fw.html Note: BVI interface is not used for management purpose. But we can add a separate Management slot/port interface that is not part of any bridge group, and that allows only management traffic to the ASA.