How to create BD in Cisco ACI

In traditional networking, we used to have VLAN as the Layer 2 forwarding domain which also define the broadcast domain. Whereas in ACI, Vlan are just an identifier and doesn’t defines the L2 domain. Bride domain defines the broadcast and L2 domain in ACI.

Like Vlan SVI in traditional network, subnets can also be defined in BD. We can also define more than one subnet under BD.

1.  Go to TENANT => HK TENANT=>Right click on BRIDGE DOMAIN => Select “CREATE BRIDGE DOMAIN”.

2. Name BD and map the VRF to this BD. Press NEXT to proceed.

3. Configure the L3 parameters and Click + to configure the subnet information under BD.

 4.      Enter the BD IP address with subnet mask. Check the “MAKE THIS IP ADDRESS    PRIMARY”.

Private to VRF—Subnet remains local to the VRF and Tenant.

Advertised Externally—Subnet can be advertised out of ACI Fabric over L3 out.

Shared between VRFs—Subnet can be exported to other VRFs in case inter-VRF routing is required.

"Treat as Virtual IP Address" option is only checked in case of multiple Fabrics.

 5. You can see subnet details will be displayed in L3 configuration section. Click NEXT to Proceed.

 6. Click Finish to create the BD