Logical network to physical network access might be required due to multiple reasons in a NSX environment:
During Physical to Virtual (P2V) migrations where changing IP addresses is not an option
Extending virtual services in the logical switch to external devices
Extending physical network services to virtual machines in logical switches
Accessing existing physical network and security resources
Since Layer 2 bridging is a NSX Edge Distributed Logical Router functionality, the L2 bridge runs on the same host on which the edge logical router control virtual machine is running. Bridging is entirely done at kernel level, as it was for Distributed Logical Routing. A special dvPort type called a sink port is used to steer packets to the bridge. In the following screenshot, we have a VXLAN environment wherein virtual machines in VXLAN network 5006 need to communicate with a physical site, which is in VLAN-100: