You can create an L2 bridge between a logical switch and a VLAN, which enables you to migrate virtual workloads to physical devices with no impact on IP addresses. A logical network can leverage a physical L3 gateway and access existing physical networks and security resources by bridging the logical switch broadcast domain to the VLAN broadcast domain.
The L2 bridge runs on the host that has the NSX Edge logical router virtual machine. An L2 bridge instance maps to a single VLAN, but there can be multiple bridge instances. The logical router cannot be used as a gateway for devices connected to a bridge.
If High Availability is enabled on the Logical Router and the primary NSX Edge virtual machine goes down, the bridge is automatically moved over to the host with the secondary virtual machine. For this seamless migration to happen, a VLAN must have been configured on the host that has the secondary NSX Edge virtual machine.
Note that you should not use an L2 bridge to connect a logical switch to another logical switch, a VLAN network to another VLAN network, or to interconnect datacenters. Also, you cannot use a universal logical router to configure bridging and you cannot add a bridge to a universal logical switch.