How to connect a network namespace to a physical network?
To connect a network namespace to the physical network, just use a bridge. In my case, I used an Open vSwitch (OVS) bridge, but a standard Linux bridge would work as well. Place one or more physical interfaces as well as one of the veth interfaces in the bridge, and—bam!—there you go.
Can a physical device be assigned to a namespace?
In addition, physical devices (those connected to real hardware) cannot be assigned to namespaces other than the root. Instead, virtual network devices (e.g. virtual ethernet or veth) can be created and assigned to a namespace.
How does the namespace persist in a network?
The namespace itself, however, will persist for as long as any processes are running within it. New network namespaces will have a loopback device but no other network devices. Aside from the loopback device, each network device (physical or virtual interfaces, bridges, etc.) can only be present in a single network namespace.
How are virtual devices used in a namespace?
Instead, virtual network devices (e.g. virtual ethernet or veth) can be created and assigned to a namespace. These virtual devices allow processes inside the namespace to communicate over the network; it is the configuration, routing, and so on that determine who they can communicate with.
How to create a network namespace in Linux?
For example, let’s say you wanted to create a namespace called “blue”. You’d use this command: To verify that the network namespace has been created, use this command: You should see your network namespace listed there, ready for you to use.
Is the IP link command a network namespace?
The ip link command will also output two lines for each device, the link status, and the characteristics. A network namespace is another copy of the network stack, with its own routes, firewall rules, and network devices. A process inherits its network namespace from its parent by default.
How to connect different namespaces to different VLANs?
Place one or more physical interfaces as well as one of the veth interfaces in the bridge, and—bam!—there you go. Naturally, if you had different namespaces, you’d probably want/need to connect them to different physical networks or different VLANs on the physical network.
Where do I Find my network namespace in Linux?
You should see your network namespace listed there, ready for you to use. Creating the network namespace is only the beginning; the next part is to assign interfaces to the namespaces, and then configure those interfaces for network connectivity.
Can you use Veth to connect network namespaces?
As a result, you can use veth interfaces to connect a network namespace to the outside world via the “default” or “global” namespace where physical interfaces exist. Let’s see how that’s done. First, you’d create the veth pair: