Routing east-west traffic between instances

In the network world, east-west traffic is traditionally defined as server-to-server traffic. In Neutron, as it relates to distributed virtual routers, east-west traffic is the traffic between instances in different networks owned by the same tenant. In the legacy model, all traffic between different networks traverses a virtual router located on a centralized network node. With DVR, the same traffic bypasses the network node and goes directly between the compute nodes hosting the virtual machine instances.

Reviewing the topology

Logically speaking, a distributed virtual router is a single router object connecting two or more tenant networks, as shown in the following diagram:

Figure 9.3

In the following example, a distributed virtual router named MyRouter-DVR is created and connected to two tenant networks: TENANT_BLUE and TENANT_RED. Virtual machine instances in each network use their respective default gateways to route traffic to the other network...