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 de-
vice 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 can provide the
netns parameter when creating the interfaces:
# ip link add <p1-name> netns <p1-ns> type veth peer <p2-name> netns <p2-ns>
or, for an existing veth pair, move one side to the other namespace:
# ip link set <p2-name> netns <p2-ns>
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
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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 2020-06-09 VETH(4)