Looks like a good option, but I ran into some problems. The routers LAN-adress change from 192.168.88.1 to one of the gateway-IP you create with this method (in my case 192.168.10.1). How to prevent that? Looks like you can't change the IP back again from "Quick settings", it sets itself back to 10.1.
It's an old thread, but hope somebody can help.

Many thanks for the article! I've just taken the plunge and ordered a RB951G hoping to achieve something similar as you describe above. My main question is still how the router "behaves" together with the modem. In a common consumer setup there is one modem and one router, but you say early on this technique can be used for WAN failover, implying multiple routers can be connected to the router. Correct? Can it also be used to completely isolate the networks from each other, while they still have internet access through one modem? I am trying to isolate my home automation and IP camera network from the main house network... Appreciate any thoughts and guidance!

Maybe I can help...
You asked: "how the router "behaves" together with the modem?."
The configuration used in this article was just like a common consumer setup with port1 connected to the internet modem, and the other 4 ports connected to the LAN. The only difference was that you will have 4 different separate LANs instead of just one.

You asked: ..." for WAN failover, implying multiple routers can be connected to the router. Correct?"...
When the author mentioned WAN failover, he just gave an example of which possibilities this nice device offers. If you want to have a WAN failover, you could connect WAN1 to port1 and WAN2 to port2 for example, and set the proper configuration for that. Then there would be only 3 ports resting for you to build up to 3 LAN subnets. Than you'd have 2 modems, but still just one router device. For each of the 3 subnets you can add cheaper switches or Access points. Not necessarily you will need routers for that.

You asked: ..." Can it also be used to completely isolate the networks from each other, while they still have internet access through one modem?"
Yes, the intention here was exactly this.

Thanks, you're the best, it works perfect!!!

How to set up speed internet for each LAN?

Nice article, I've been researching the last part which is to make the different networks talk but no luck. I'm testing two networks they can ping each interface ip but no the computer connect to those interfaces. Any suggestions?

The article suggests from the picture of the winbox interface list that the default RB750GL configuration has been loaded. If you then make changes as suggested from the out of the box default configuration the subnets will not see each other(as you seemed to have experienced). You need to do a reset configuration and tick no-default and reboot and then rebuild with winbox as per above.

Otherwise if you have made changes from the out of the box default configuration you will need to add to ip firewall nat

add action=masquerade chain=srcnat comment="to allow ping to subnet" out-interface=!ether2-master-local src-address=192.168.2.0/24
add action=masquerade chain=srcnat comment="to allow ping to subnet" \ out-interface=!ether3-slave-local src-address=192.168.3.0/24
and so on for each ether port and subnet
and then should be able to ping each subnet. I did document this previously but the other 33 posts to this thread have vanished.

Russel,

Why does one have to reset the configuration? What setting is causing the routes not to communicate across one another?

I just became MTCNA certified and you might imagine, the instructors didn't go over multiple networks on a single router like this. (They did go over static routes for multiple routers)

Any suggestions?

Really nice article. I was confused that I couldn't ping a machine on a different network. Turns out I didn't have the default gateway setup on the receiving machine.

Nice article! My question is: No changes are needed in the Firewall? Are all 4 subnets still protected?