.. _dummy-interface: ##### Dummy ##### The dummy interface is really a little exotic, but rather useful nevertheless. Dummy interfaces are much like the :ref:`loopback-interface` interface, except you can have as many as you want. .. note:: Dummy interfaces can be used as interfaces that always stay up (in the same fashion to loopbacks in Cisco IOS), or for testing purposes. .. hint:: A Dummy interface is always up, thus it could be used for management traffic or as source/destination for and :abbr:`IGP (Interior Gateway Protocol)` like :ref:`bgp` so your internal BGP link is not dependent on physical link states and multiple routes can be chosen to the destination. A :ref:`dummy-interface` Interface should always be preferred over a :ref:`loopback-interface` interface. Configuration ############# Common interface configuration ------------------------------ .. cmdinclude:: ../_include/interface-address.txt :var0: dummy :var1: dum0 .. cmdinclude:: ../_include/interface-description.txt :var0: dummy :var1: dum0 Operation ========= .. opcmd:: show interfaces dummy Show brief interface information.information .. code-block:: none vyos@vyos:~$ show interfaces dummy Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down Interface IP Address S/L Description --------- ---------- --- ----------- dum0 172.18.254.201/32 u/u .. opcmd:: show interfaces dummy Show detailed information on given `` .. code-block:: none vyos@vyos:~$ show interfaces ethernet eth0 dum0: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 26:7c:8e:bc:fc:f5 brd ff:ff:ff:ff:ff:ff inet 172.18.254.201/32 scope global dum0 valid_lft forever preferred_lft forever inet6 fe80::247c:8eff:febc:fcf5/64 scope link valid_lft forever preferred_lft forever RX: bytes packets errors dropped overrun mcast 0 0 0 0 0 0 TX: bytes packets errors dropped carrier collisions 1369707 4267 0 0 0 0