For an Ethernet frame to travel from a virtual machine instance to a device on the physical network, it will pass through three or four devices inside the host:
Network type |
Interface type |
Interface name |
all |
tap |
tapN |
all |
bridge |
brqXXXX |
vxlan |
vxlan |
vxlan-z (where Z is the VNI) |
vlan |
vlan |
ethX.Y (where X is the physical interface and Y is the VLAN ID) |
flat, vlan |
physical |
ethX (where X is the interface) |
To help conceptualize how Neutron uses Linux bridges, a few examples of Linux bridge architectures are provided in the following sections.