Configuration Overview

VyOS makes use of a unified configuration file for all system configuration: config.boot. This allows for easy template creation, backup, and replication of system configuration.

The current active configuration -aka running configuration- can be viewed using the show configuration command.

vyos@vyos:~$ show configuration
interfaces {
    ethernet eth0 {
        address dhcp
        hw-id 00:0c:29:44:3b:0f
    loopback lo {
service {
    ssh {
        port 22
system {
    config-management {
        commit-revisions 20
    console {
        device ttyS0 {
            speed 9600
    login {
        user vyos {
            authentication {
                encrypted-password ****************
            level admin
    ntp {
        server {
        server {
        server {
    syslog {
        global {
            facility all {
                level notice
            facility protocols {
                level debug

By default the configuration is displayed in a hierarchy like the example above, this is only one of the possible ways to display the configuration.

When the configuration is generated and the device is configured, changes are added through a collection of set and delete commands. You can see that collection of commands by entering show configuration commands, which is another way of seeing the running configuration.

vyos@vyos:~$ show configuration commands
set interfaces ethernet eth0 address 'dhcp'
set interfaces ethernet eth0 hw-id '00:0c:29:44:3b:0f'
set interfaces loopback 'lo'
set service ssh port '22'
set system config-management commit-revisions '20'
set system console device ttyS0 speed '9600'
set system login user vyos authentication encrypted-password '<removed>'
set system login user vyos level 'admin'
set system ntp server ''
set system ntp server ''
set system ntp server ''
set system syslog global facility all level 'notice'
set system syslog global facility protocols level 'debug'

Both these commands should be executed when in operational mode, they do not work in configuration mode.

Configuration terminology

A VyOS system has three major types of configurations:

Active or running configuration

The active or running configuration is the system configuration that is loaded and currently being used by VyOS. Any change in the configuration will have to be committed to belong to the active/running configuration.

Working configuration

The working configuration is the configuration which is currently being modified in configuration mode. Changes made to the working configuration do not go into effect until the changes are committed with the commit command. At which time the working configuration will become the active or running configuration.

Saved configuration

A saved configuration is a configuration saved to a file using the save command. It allows you to keep safe a configuration for future uses. There can be multiple configuration files. The default or “boot” configuration is saved and loaded from the file config.boot.

Managing the configuration

The configuration is managed by the use of set and delete commands from within configuration mode. Configuration commands are flattened from the tree into ‘one-liner’ commands shown in show configuration commands from operation mode.

These commands are also relative to the level where they are executed and all redundant information from the current level is removed from the command entered.

vyos@vyos# set interface ethernet eth0 address

[edit interfaces ethernet eth0]
vyos@vyos# set address

These two commands above are essentially the same, just executed from different levels in the hierarchy.

To delete a configuration entry use the delete command, this also deletes all sub-levels under the current level you’ve specified in the delete command. Deleting an entry will also result in the element reverting back to its default value if one exists.

[edit interfaces ethernet eth0]
vyos@vyos#  delete address

Any change you do on the configuration, will not take effect until committed using the commit command in configuration mode.

vyos@vyos# commit
vyos@vyos# exit
Warning: configuration changes have not been saved.

In order to preserve configuration changes upon reboot, the configuration must also be saved once applied. This is done using the save command in configuration mode.

vyos@vyos# save
Saving configuration to '/config/config.boot'...

Configuration mode can not be exited while uncommitted changes exist. To exit configuration mode without applying changes, the exit discard command can be used.

vyos@vyos# exit
Cannot exit: configuration modified.
Use 'exit discard' to discard the changes and exit.
vyos@vyos# exit discard
vyos@vyos# save [tab]
Possible completions:
  <Enter>       Save to system config file
  <file>        Save to file on local machine
  scp://<user>:<passwd>@<host>/<file> Save to file on remote machine
  ftp://<user>:<passwd>@<host>/<file> Save to file on remote machine
  tftp://<host>/<file>      Save to file on remote machine
vyos@vyos# save tftp://
Saving configuration to 'tftp://'...
######################################################################## 100.0%

Operational info from config mode

When inside configuration mode you are not directly able to execute operational commands.

Access to these commands are possible through the use of the run [command] command. From this command you will have access to everything accessible from operational mode.

Command completion and syntax help with ? and [tab] will also work.

vyos@vyos# run show interfaces
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
eth0                            u/u

Configuration archive

VyOS automatically maintains backups of previous configurations.

Local archive and revisions

Revisions are stored on disk. You can view them, compare them, and rollback to previous revisions if anything goes wrong.

To view existing revisions, use show system commit operational mode command.

vyos@vyos-test-2# run show system commit
0   2015-03-30 08:53:03 by vyos via cli
1   2015-03-30 08:52:20 by vyos via cli
2   2015-03-26 21:26:01 by root via boot-config-loader
3   2015-03-26 20:43:18 by root via boot-config-loader
4   2015-03-25 11:06:14 by root via boot-config-loader
5   2015-03-25 01:04:28 by root via boot-config-loader
6   2015-03-25 00:16:47 by vyos via cli
7   2015-03-24 23:43:45 by root via boot-config-loader

To compare configuration revisions in configuration mode, use the compare command:

vyos@vyos# compare [tab]
Possible completions:
  <Enter>     Compare working & active configurations
  saved               Compare working & saved configurations
  <N>         Compare working with revision N
  <N> <M>     Compare revision N with M
    0    2013-12-17 20:01:37 root by boot-config-loader
    1    2013-12-13 15:59:31 root by boot-config-loader
    2    2013-12-12 21:56:22 vyos by cli
    3    2013-12-12 21:55:11 vyos by cli
    4    2013-12-12 21:27:54 vyos by cli
    5    2013-12-12 21:23:29 vyos by cli
    6    2013-12-12 21:13:59 root by boot-config-loader
    7    2013-12-12 16:25:19 vyos by cli
    8    2013-12-12 15:44:36 vyos by cli
    9    2013-12-12 15:42:07 root by boot-config-loader
    10   2013-12-12 15:42:06 root by init


Comparing Revisions

You can compare revisions with compare X Y command, where X and Y are revision numbers. The output will describe how the configuration X is when compared to Y, indicating with a plus sign (+) the additional parts X has when compared to y, and indicating with a minus sign (-) the lacking parts x misses when compared to y.

vyos@vyos-test-2# compare 0 6
[edit interfaces]
+dummy dum1 {
+    address
[edit interfaces ethernet eth0]
+vif 99 {
+    address
-vif 900 {
-    address

Rolling Back Changes

You can rollback configuration using the rollback command. This command will apply the selected revision and trigger a system reboot.

vyos@vyos# compare 1
[edit system]
>host-name vyos-1
vyos@vyos# rollback 1
Proceed with reboot? [confirm][y]
Broadcast message from root@vyos-1 (pts/0) (Tue Dec 17 21:07:45 2013):
The system is going down for reboot NOW!

Configuring the archive size

You can specify the number of revisions stored on disk with set system config-management commit-revisions X, where X is a number between 0 and 65535. When the number of revisions exceeds that number, the oldest revision is removed.

Remote archive

VyOS can copy the config to a remote location after each commit. TFTP, FTP, and SFTP servers are supported.

You can specify the location with:

  • set system config-management commit-archive location URL

For example, set system config-management commit-archive location tftp://

You can specify the location with set system config-management commit-archive location URL command, e.g. set system config-management commit-archive location tftp://

Wipe config and restore default

In the case you want to completely delete your configuration and restore the default one, you can enter the following command in configuration mode:

load /opt/vyatta/etc/config.boot.default

You will be asked if you want to continue. If you accept, you will have to use commit if you want to make the changes active.

Then you may want to save in order to delete the saved configuration too.


If you are remotely connected, you will lose your connection. You may want to copy first the config, edit it to ensure connectivity, and load the edited config.