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.. _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:: On systems with multiple redundant uplinks and routes,
it's a good idea to use a dedicated address for management and dynamic routing protocols.
However, assigning that address to a physical link is risky:
if that link goes down, that address will become inaccessible.
A common solution is to assign the management address to a loopback or a dummy interface
and advertise that address via all physical links, so that it's reachable
through any of them. Since in Linux-based systems, there can be only one loopback interface,
it's better to use a dummy interface for that purpose, since they can be added, removed,
and taken up and down independently.
*************
Configuration
*************
Common interface configuration
==============================
.. cmdinclude:: /_include/interface-address.txt
:var0: dummy
:var1: dum0
.. cmdinclude:: /_include/interface-description.txt
:var0: dummy
:var1: dum0
.. cmdinclude:: /_include/interface-disable.txt
:var0: dummy
:var1: dum0
.. cmdinclude:: /_include/interface-vrf.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 <interface>
Show detailed information on given `<interface>`
.. code-block:: none
vyos@vyos:~$ show interfaces ethernet eth0
dum0: <BROADCAST,NOARP,UP,LOWER_UP> 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
|
