NETWORK_NAMESPACES(7) Linux Programmer's Manual NETWORK_NAMESPACES(7)NAME
network_namespaces - overview of Linux network namespaces
DESCRIPTION
Network namespaces provide isolation of the system resources associated with networking: network devices, IPv4 and IPv6 protocol stacks, IP
routing tables, firewall rules, the /proc/net directory (which is a symbolic link to /proc/PID/net), the /sys/class/net directory, various
files under /proc/sys/net, port numbers (sockets), and so on.
A physical network device can live in exactly one network namespace. When a network namespace is freed (i.e., when the last process in the
namespace terminates), its physical network devices are moved back to the initial network namespace (not to the parent of the process).
A virtual network (veth(4)) device pair provides a pipe-like abstraction that can be used to create tunnels between network namespaces, and
can be used to create a bridge to a physical network device in another namespace. When a namespace is freed, the veth(4) devices that it
contains are destroyed.
Use of network namespaces requires a kernel that is configured with the CONFIG_NET_NS option.
SEE ALSO nsenter(1), unshare(1), clone(2), veth(4), proc(5), sysfs(5), namespaces(7), user_namespaces(7), brctl(8), ip(8), ip-address(8), ip-
link(8), ip-netns(8), iptables(8), ovs-vsctl(8)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2018-02-02 NETWORK_NAMESPACES(7)
Check Out this Related Man Page
veth(4) Linux Programmer's Manual veth(4)NAME
veth - Virtual Ethernet Device
DESCRIPTION
The veth devices are virtual Ethernet devices. They can act as tunnels between network namespaces to create a bridge to a physical network
device in another namespace, but can also be used as standalone network devices.
veth devices are always created in interconnected pairs. A pair can be created using the command:
# ip link add <p1-name> type veth peer name <p2-name>
In the above, p1-name and p2-name are the names assigned to the two connected end points.
Packets transmitted on one device in the pair are immediately received on the other device. When either devices is down the link state of
the pair is down.
veth device pairs are useful for combining the network facilities of the kernel together in interesting ways. A particularly interesting
use case is to place one end of a veth pair in one network namespace and the other end in another network namespace, thus allowing communi-
cation between network namespaces. To do this, one first creates the veth device as above and then moves one side of the pair to the other
namespace:
# ip link set <p2-name> netns <p2-namespace>
ethtool(8) can be used to find the peer of a veth network interface, using commands something like:
# ip link add ve_A type veth peer name ve_B # Create veth pair
# ethtool -S ve_A # Discover interface index of peer
NIC statistics:
peer_ifindex: 16
# ip link | grep '^16:' # Look up interface
16: ve_B@ve_A: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc ...
SEE ALSO clone(2), network_namespaces(7), ip(8), ip-link(8), ip-netns(8)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2018-02-02 veth(4)
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