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85 lines
2.7 KiB
ReStructuredText
85 lines
2.7 KiB
ReStructuredText
:lastproofread: 2023-01-20
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.. _dummy-interface:
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#####
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Dummy
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#####
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The dummy interface is really a little exotic, but rather useful nevertheless.
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Dummy interfaces are much like the :ref:`loopback-interface` interface, except
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you can have as many as you want.
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.. note:: Dummy interfaces can be used as interfaces that always stay up (in
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the same fashion to loopbacks in Cisco IOS), or for testing purposes.
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.. hint:: On systems with multiple redundant uplinks and routes,
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it's a good idea to use a dedicated address for management and dynamic routing protocols.
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However, assigning that address to a physical link is risky:
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if that link goes down, that address will become inaccessible.
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A common solution is to assign the management address to a loopback or a dummy interface
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and advertise that address via all physical links, so that it's reachable
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through any of them. Since in Linux-based systems, there can be only one loopback interface,
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it's better to use a dummy interface for that purpose, since they can be added, removed,
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and taken up and down independently.
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*************
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Configuration
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*************
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Common interface configuration
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==============================
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.. cmdinclude:: /_include/interface-address.txt
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:var0: dummy
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:var1: dum0
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.. cmdinclude:: /_include/interface-description.txt
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:var0: dummy
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:var1: dum0
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.. cmdinclude:: /_include/interface-disable.txt
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:var0: dummy
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:var1: dum0
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.. cmdinclude:: /_include/interface-vrf.txt
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:var0: dummy
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:var1: dum0
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*********
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Operation
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*********
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.. opcmd:: show interfaces dummy
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Show brief interface information.
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.. code-block:: none
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vyos@vyos:~$ show interfaces dummy
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Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
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Interface IP Address S/L Description
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--------- ---------- --- -----------
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dum0 172.18.254.201/32 u/u
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.. opcmd:: show interfaces dummy <interface>
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Show detailed information on given `<interface>`
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.. code-block:: none
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vyos@vyos:~$ show interfaces dummy dum0
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dum0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
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link/ether 26:7c:8e:bc:fc:f5 brd ff:ff:ff:ff:ff:ff
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inet 172.18.254.201/32 scope global dum0
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valid_lft forever preferred_lft forever
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inet6 fe80::247c:8eff:febc:fcf5/64 scope link
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valid_lft forever preferred_lft forever
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RX: bytes packets errors dropped overrun mcast
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0 0 0 0 0 0
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TX: bytes packets errors dropped carrier collisions
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1369707 4267 0 0 0 0
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