veth - Virtual Ethernet Device

       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:

           # iplinkaddve_Atypevethpeernameve_B   # Create veth pair
           # ethtool-Sve_A         # Discover interface index of peer
           NIC statistics:
                peer_ifindex: 16
           # iplink|grep'^16:'   # Look up interface
           16: ve_B@ve_A: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc ...

       veth - Virtual Ethernet Device

clone(2), network_namespaces(7), ip(8), ip-link(8), ip-netns(8)

Linux man-pages 6.9.1                              2024-05-02                                            veth(4)