Introduction · Topic 8 of 8

Resetting a Router and Reinstalling with Netinstall

Learn how to reset a RouterOS device to defaults or to a blank state, and how Netinstall reinstalls RouterOS from a PC when a router cannot boot normally.

4 min

In a nutshell

/system reset-configuration returns the router to its default configuration.
no-defaults=yes gives a blank router, and keep-users=yes keeps the accounts.
run-after-reset runs a script file after the reset.

What it is

Resetting clears the configuration, and Netinstall reinstalls the operating system itself.

A reset keeps RouterOS but removes the configuration, either back to the default configuration or to a completely blank router. Netinstall is a PC tool that installs RouterOS over the network cable, even when the router is not working normally.

Use a reset for a clean start, and Netinstall when a reset is not enough.

How it works

A reset is a command or a button, and Netinstall needs a PC and a cable.

Resetting from the console

The reset command has options that decide what is left afterwards.

/system reset-configuration
/system reset-configuration no-defaults=yes skip-backup=yes
/system reset-configuration keep-users=yes
/system reset-configuration run-after-reset=my-config.rsc

Option	Effect
no-defaults	Start completely blank, without the default configuration
skip-backup	Do not make an automatic backup before the reset
keep-users	Keep the user accounts
run-after-reset	Run a script file after the reset finishes

Without options the router returns to its default configuration. With no-defaults=yes it comes up empty, with no addresses and no firewall, so you must reach it by MAC-WinBox or the serial console.

The run-after-reset option is useful for rebuilding a router. Upload an edited export file, name it in the command, and the router configures itself after the reset.

Watch out

A blank router has no IP address, so be ready to reconnect by MAC address or by the serial console.

Resetting with the hardware button

Most RouterBOARD devices have a reset button. You hold it while the router powers on, and the router reacts to how long you hold it.

The timing and the LED behaviour differ between models, so check the documentation for your device. The usual outcomes are a reset to the default configuration, or a boot into a mode where Netinstall can reach the router.

The button is the way back in when you forget the password and have no other access.

Netinstall

Netinstall is a program that runs on a PC and installs RouterOS on a router over Ethernet. It is available for Windows and also for Linux.

It is used when:

the router no longer boots RouterOS,
an upgrade was interrupted,
the password is lost and no other way in works,
you want a completely fresh install.

The procedure follows these steps:

Connect the PC directly to the Ethernet port of the router that supports network booting, usually the first port. Check the model documentation.
Give the PC a fixed IP address and run Netinstall.
Put the router into network boot mode, for example with the reset button while powering on.
When the router appears in the Netinstall list, select it.
Choose the RouterOS package files to install, and start the install.
When it finishes, the router reboots with a fresh system.

Netinstall removes the old configuration unless you choose the option to keep it. After the install you configure the router again, or restore a saved backup or export.

Reset or Netinstall

Situation	Choice
Want a clean configuration, router works	Reset
Router will not boot RouterOS	Netinstall
Want to restore the same state quickly	Backup load
Want a clean install of a chosen RouterOS version	Netinstall

What to remember for the exam

Six facts cover this topic.

/system reset-configuration returns the router to its default configuration.
no-defaults=yes gives a blank router, and keep-users=yes keeps the accounts.
run-after-reset runs a script file after the reset.
The reset button works while the router powers on, and the behaviour depends on the model.
Netinstall is a PC tool that installs RouterOS over the Ethernet cable.
Netinstall is for recovery, and it wipes the configuration unless you choose to keep it.

Watch out

Netinstall needs a direct cable and a fixed PC address, so a switch with other traffic or a firewall on the PC can stop it from finding the router.

Common mistakes

These four mistakes cause trouble.

Resetting without a saved export. The configuration is lost, so save an export first.

Using no-defaults and then having no access. A blank router has no address, so use MAC-WinBox or the serial console.

Choosing the wrong port for Netinstall. The router boots from the network on one specific port, so check the model notes.

Treating a reset as a fix for a boot failure. A reset needs a working RouterOS. When the system will not start, use Netinstall.

Check yourself

Work through these three questions.

What does no-defaults=yes do in a reset?
It makes the router start completely blank, without the default configuration. You then need MAC-WinBox or the serial console to reach it.
When is Netinstall the right tool?
Use it when the router will not boot RouterOS, an upgrade failed, or you need a fresh install. It installs RouterOS from a PC over the Ethernet cable.
How can a reset rebuild a router automatically?
Use run-after-reset with a script file name. The router runs that file after the reset finishes.

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