An example network orchestrator includes processing circuitry and a memory including instructions that, when executed by the processing circuitry, cause the network orchestrator to determine that a branch site of a WAN includes multiple branch gateways. The network orchestrator further determines that devices of a core site of the WAN and devices of the branch site are members of an extended VLAN. The network orchestrator further transmits a first command to a first branch gateway and a first headend gateway to establish a WAN uplink tunnel to forward data traffic of the extended VLAN. The network orchestrator further transmits a second command to a set of branch gateways of the branch gateway cluster to establish intracluster tunnels with the first branch gateway.