Hi!
There is Mikrotik RB2011L-RM + 2 internet connections pppoe (Use peer DNS - activated)
ETH1 - main Internet
ETH2 - reserv

When eth1 is disabled - DNS (IP - DNS) set from provider2 (eth2).
And when eth1 is enabled - DNS set from provider1 (eth1).

But also i want add DNS from google: 4.4.4.4 and 8.8.8.8.
When eth1/eth2 switch - DNS 4.4.4.4 and 8.8.8.8 is dissapear.

Where can i set static DNS-servers?

If you're using winbox, you should be able to go to IP > DNS and then manually add the servers with the down arrows to add lines.

Are you trying to use only dns from google? or do you want your ISP dns + google dns?

No, I'm not. I would like to use ISP dns + google dns.
When i opened IP -> DNS first time, there was automatically DNS from ISP connection. (pppoe-out1). I've added lines and written google DNS.
Then I've simulated disconect ISP (eth1) - disabled it. Internet has gone throught ISP2 (eth2). But DNS has updated automatically (remained only DNS from ISP2).

Do you advice me try only google dns?

Does anyone know whether the static servers are always queried in the same order or if they are used round-robin even if there are no failures?

I can open a new thread if needed (and was about to), this was just pretty closely related.

No I'm not. I would like to use ISP dns + Google dns.
When i've opened IP -> DNS first time, there were automatically DNS from ISP1 (eth1). I've added lines for dns and written google DNS.
Then, i've simulated disconnect (turn off ISP1 (eth1)) and Internet switched on ISP2 (eth2).
I've opened IP -> DNS but there were only automatically DNS from ISP2 (eth2). Google DNS has disappeared.

Do you advance me try only google DNS and turn off Use peer DNS on both ISP?