Dual WAN failover

Hi guys!

I know there is hundred and hundred topics about it… but i need to manage a dual wan failover connection.

I have done something like this:

eth1 pppoe-client1 with Default route distance=1
eth2 pppoe-client2 with Default route distance=2

and 3-4-5 in bridge with 192.168.1.1/24 (classical lan configuration)

normally, everything’s working like this:
img1.png
I have some more or less 20 customers with this kind of setup, and randomly i have this problem:
img2.png
In this case, all my LAN connection goes to wan2 (eth2)

..to solve, simply disable and renable the interface or reboot the rb and everyhting’s is ok.

any idea of what happens or to solve better?

Thank to all!
img2.png