Is it possible on MikroTik OS to set up 3G (over USB) connection as an automatic backup if internet connection via PPPoE connection breaks.

Howdy,

yes it is possible. I set this up quickly as a test on our office router recently.

Basically you assign a default route using, for example ppp-out1 as the 3G connection, and assign a larger distance than the pppoe connection.

For example:

/ip route
add check-gateway=ping disabled=no distance=1 dst-address=0.0.0.0/0 gateway=aaa.bbb.ccc.ddd scope=30 target-scope=10
add disabled=yes distance=2 dst-address=0.0.0.0/0 gateway=ppp-out1 scope=30 target-scope=10

The second entry is disabled as I an not actually using it now. The distance is set to 2 which is larger than 1 so this route will be used as a backup.

Of course your gateway will be different.

Hope this helps.

Thanks. It is working well.

Hi I am trying to do this but I have a problem with this scenario. The routes are assigned dynamically.
Any ideas.

Hi I am trying to do this but I have a problem with this scenario. The routes are assigned dynamically.
Any ideas.

Hi
I had same issues, but I figured out that the dynamic routes for ppp-out connections are managed on the interface dialog.

You can set the default-rout distance (for dynamically associated route) from the PPP menu under your ppp-out1 interface settings.

Good luck