blob: 77b6e47577ec87dbe72b40e643f8f9c76acc2e0f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
:lastproofread: 2026-01-23
.. _loopback-interface:
########
Loopback
########
The loopback interface is a virtual, software-based network interface. All
traffic sent to it loops back and only targets services on the local host.
.. note:: Only one loopback ``lo`` interface is allowed per operating system.
If you require multiple virtual interfaces, use the :ref:`dummy-interface`
interface type.
.. hint:: The loopback interface is always operational, making it suitable for
management traffic or as a stable source/destination for routing protocols such
as BGP. This ensures internal routing sessions remain independent of physical
link states.
However, in most cases, the dummy interface is preferred over the loopback
interface.
*************
Configuration
*************
Common interface configuration
==============================
.. cmdinclude:: /_include/interface-address.txt
:var0: loopback
:var1: lo
.. cmdinclude:: /_include/interface-description.txt
:var0: loopback
:var1: lo
*********
Operation
*********
.. opcmd:: show interfaces loopback
Show brief interface information.
.. code-block:: none
vyos@vyos:~$ show interfaces loopback
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
lo 127.0.0.1/8 u/u
::1/128
.. opcmd:: show interfaces loopback lo
Show detailed interface information.
.. code-block:: none
vyos@vyos:~$ show interfaces loopback lo
lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
RX: bytes packets errors dropped overrun mcast
300 6 0 0 0 0
TX: bytes packets errors dropped carrier collisions
300 6 0 0 0 0
|
