veth(4)                      Device Drivers 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 device 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
       communication 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)

Linux man-pages 6.7               2023-10-31                           veth(4)