Watchdog

CLI reference:/system/watchdog

The watchdog reboots the router by itself in two cases, each with its own settings in /system/watchdog:

• The software watchdog timer reboots the router when the system stops responding. This is mostly caused by a hardware malfunction, and the reboot lets the device recover by itself. It is on by default (watchdog-timer=yes).
• The ping watchdog reboots the router when one IP address stops answering pings. It is off by default (watch-address=none).

A watchdog reboot is an automatic /system/reboot, not a software failure. The watchdog timer reboots the router because a service does not respond as fast as it should. Reasons can be damaged hardware, a slow software implementation of a service, a DDoS attack, a bad configuration and others.

Reboot when an address stops answering

A remote router can lose its uplink or its VPN and stay unreachable until someone restarts it, for example a router on a mast whose wireless link hangs. The ping watchdog reboots such a router when an address on the other side of the link stops answering:

/system/watchdog/set watch-address=192.0.2.1

Use an address that is reliably up and that the router reaches through the link you care about, such as the gateway of the uplink. For a VPN, watch an address inside the tunnel, such as the tunnel address of the far end, not its public address: the public address can still answer when the tunnel is down. An address that is down for its own reasons reboots a router that works.

The router pings the address six times, spread over ping-timeout (1 minute by default, so one ping every 10 seconds), and reboots when all six pings fail. After a boot, it waits ping-start-after-boot (5 minutes by default) before the first ping. On a router that has been up longer than ping-start-after-boot, setting watch-address starts the pings at once.

Set ping-start-after-boot longer than the link needs to come up after a boot, for example a VPN or an LTE connection. Otherwise the router reboots before the link is up. After each reboot, this time is also your window to log in and set watch-address=none.

warning

If the address stays unreachable, the router reboots again after each boot, every ping-start-after-boot plus ping-timeout: about every 6 minutes with the defaults. Choose the address carefully, and keep another way in, such as console access or MAC Telnet from a neighbor.

To turn the ping watchdog off:

/system/watchdog/set watch-address=none

The ping watchdog reboots for as long as the address does not answer. For a limited number of reboots, or for other actions when an address stops answering, use Netwatch with a script.

See why the router rebooted

After a ping watchdog reboot, the log shows these entries (topics system,error,critical for the first one):

System rebooted because of ping watchdog timeout
router rebooted

A ping watchdog reboot does not write a support output file (autosupout.rif).

Support output after a crash

When the software fails, the router writes autosupout.rif by itself (automatic-supout=yes, on by default) and renames the previous file to autosupout.old.rif. Send these files to MikroTik support with the problem description. For more about support output files, see Supout.rif.

The router can also send the file by email. For example, to send it to support@example.com through the SMTP server 192.0.2.1:

/system/watchdog/set auto-send-supout=yes \
    send-email-to=support@example.com send-smtp-server=192.0.2.1

When send-email-from or send-smtp-server is not set, the router uses the values from /tool/e-mail. While auto-send-supout=no, print does not show the email settings.

Technical details

Ping interval

The interval between the pings is ping-timeout divided by six: 10 seconds with the default 1m, 20 seconds with 2m. The reboot follows a few seconds after the sixth failed ping, so it comes about ping-timeout after the first failed ping.

Older exports call ping-start-after-boot no-ping-delay.

Software watchdog timer

With watchdog-timer=yes, the router reboots when the system is unresponsive for a minute. Set watchdog-timer=no to turn it off.

For all parameters, see the /system/watchdog CLI reference.