What are Linux Namespaces

A namespace wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource.

There are 7 namespaces in Linux:

• Cgroup: cgroup = control group. Resource limiting, prioritization, accounting and control.
• IPC: Inter-process Communication.
• Network: Network devices, ports, etc.
• Mount: Mount points (of file systems).
• PID: Process IDs.
• User: User and group IDs.
• UTS: UNIX Timesharing System, named after the data structure used to store info returned by uname system call. Isolates hostname and NIS domain name.

cgroup

Read more: cgroup

Network Namespaces

Each network namespace has its own localhost and loopback (lo) device. If loopback device is not up, localhost would not work.

# List network namespaces
$ ip netns list

# Add network namespace
$ ip netns add NAMESPACE