The Linux operating system has a single routing table and global set of network interfaces. Network namespace scales this limitation by providing independent instances of network interfaces and routing tables. This feature enables network isolation and independent operation of multiple network instances. The following diagram depicts network topology with OVS interconnecting hosts isolated by network:
Figure 1: Network topology with OVS connecting with Network namespace hosts
The network interface within the namespace interconnects with Virtual Ethernet Port of open vSwitch via Virtual Ethernet (VETH) port pair. Virtual Ethernet ports are equivalent to a pair of physical Ethernet interfaces interconnected by a cable, albeit implemented purely using software. Virtual Ethernet is implemented as tunnel driver working at link layer (L2) connecting pair of Virtual Ethernet ports.
In this example, we will create two network namespaces and interconnect...