Office router with NAT and 2 ISPs - fail-over only

RouterOS General
1

Hi!

I have RB2011UiAS-2HnD-IN with LAN PCs behind NAT and two uplinks with static IPs. I don’t need load-balancing, only fail-over, i.e. when one ISP fails (link down, no replies from default GW, no internet, etc) router should switch default gw and out interface in masquerade rule to other ISP and vice versa.

What is best suggested approach?

2

I wonder if using scripts is the only way to solve this.

3

If you don’t like scripts, you may try recursive routing
http://wiki.mikrotik.com/wiki/Advanced_Routing_Failover_without_Scripting

4

Thanks, I have nothing against scripts, but I don’t know what to do with NAT. Change out interface on ISP failure?

5

src-nat follow AFTER routing decision. No need to decide in nat rules, which interface should transmit traffic - it’s already decided. So, just make nat on both (WAN1 and WAN2) interfaces and that’s all.