Single interface
For hosts using a single interface, all traffic to and from instances as well as internal OpenStack, SSH management, and API traffic traverse the same physical interface. This configuration can result in severe performance penalties, as a service or guest can potentially consume all available bandwidth. A single interface is recommended only for non-production clouds.
The following table demonstrates the networks and services traversing a single interface over multiple VLANs:
Service/function |
Purpose |
Interface |
VLAN |
SSH |
Host management |
eth0 |
10 |
APIs |
Access to OpenStack APIs |
eth0 |
15 |
Overlay network |
Used to tunnel overlay (VXLAN, GRE, GENEVE) traffic between hosts |
eth0 |
20 |
Guest/external network(s) |
Used to provide access to external cloud resources and for VLAN-based project networks |
eth0 |
Multiple |