Which of the following typically defines a Layer 2 address space and flood domain within a Cisco ACI fabric?
- an application profile
- a VRF instance
- a bridge domain
- an EPG
Of the available choices, a bridge domain typically defines a Layer 2 address space and flood domain within a Cisco Application Centric Infrastructure (ACI) fabric. An ACI bridge domain is similar to a traditional networking virtual local area network (VLAN) in that it is an Open Systems Interconnection (OST) networking model Layer 2 broadcast domain. Bridge domains define the Media Access Control (MAC) address space. Typically, a bridge domain is associated with a single subnet, although multiple subnets can be associated within a given bridge domain. Bridge domains are typically connected to virtual routing and forwarding (VRF) instances within a given ACI tenant.
A VRF instance is a Layer 3 forwarding domain within a given ACI tenant. VRF instances are also known as contexts or private networks. Multiple bridge domains can be connected to a given VRF instance within a tenant.
An application profile is used to configure policies and relationships between endpoint groups (EPGs). Typically, an application profile is a container for one or more logically related EPGs. For example, EPGs that provide similar services or functions might be associated with the same application profile.
An EPG is a logical ACI construct that contains multiple related endpoints. Endpoints are physical or virtual devices that are connected to a network. For example, a web server is an endpoint. EPGs contain endpoints that have similar policy requirements, although not necessarily similar functions. EPGs enable group management of the policies for the endpoints they contain.