https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric- infrastructure/white-paper-c07-732033.html#_Toc395143568 There are several different ways to extend layer 2 domain beyond the ACI fabric:
* Extend the EPG out of the ACI fabric - A user can extend an EPG out of the ACI fabric by statically assigning a port (along with VLAN ID) to an EPG. The leaf will learn the endpoint information and assign the traffic (by matching the port and VLAN ID) to the proper EPG, and then enforce the policy. The endpoint learning, data forwarding, and policy enforcement remain the same whether the endpoint is directly attached to the leaf port or if it is behind a layer 2 network (provided the proper VLAN is enabled in the layer2 network).
* Extend the bridge domain out of the ACI fabric - Another option to extend the layer 2 domain is to create a layer 2 outside connection (or external bridged network, as called in the APIC GUI) for a given bridge domain. It effectively extends the bridge domain to the outside network.
* Extend the layer 2 domain with remote VTEP (future) - In the previous two options the incoming traffic from outside is tagged with a VLAN ID. The ACI leaf classifies the traffic to the proper EPG by checking the port and VLAN ID. In future software releases, the remote VTEP will be supported, and can be used to extend the EPG or bridge domain.
The following sections explain these three options in greater detail.
Extend the EPG Out of the ACI Fabric
The user can extend an EPG beyond an ACI leaf by statically assigning a leaf port (along with a VLAN ID) to an EPG. After doing so, all the traffic received on this leaf port with the configured VLAN ID will be mapped to the EPG and the configured policy for this EPG will be enforced. The endpoints need not be directly connected to the ACI leaf port. They can be behind a layer 2 network as long as the VLAN associated with the EPG is enabled within the layer 2 network that connects the remote endpoint to the ACI fabric.
To statically assign port to an EPG, go to menu TenantaApplication ProfilesaEPGaStatic Binding (Paths). Click the Action menu on the right side to start to assign port to an EPG. Figure 50 provides an example that assigns interface eth1/26 from the leaf node 101 along with VLAN 3 to EPG WEB.