Hello Guys
I have like the basic knowledge of networking
I bought a RB 1100 as I was told it can do the following:
I have a building with multiple networks
(192.168.1.1 - 10.10.10.1 - 192.168.2.1 -192.168.0.1 - 192.168.1.1)
They are local networks for each flats individually
I want to connect all those flats to one camera down stairs
NETWORKS > RB 1100 router < Camera
Networks should be able to see each others however sees the camera
and as you may notice some of the networks have same network
So how would I start with my RB 1100 
Are those localnets behind a router in each flat? Do the routers perform a NAT on the interface connected to your RB1100?
Yes there is a router in each flat
And I can have a NAT on the port connected to the RB1100
Then the flats will not be able to connect to the other flat’s network, but should be able to see the camera. Is that what you want?
Ok. Put all the routers on one interface (like switch or bridge) with a dhcp server. All routers in the flats get an ip from the dhcp server. Assign the camera a static ip, either on the same interface, or its own interface and localnet. If you use the same localnet for the camera, insure it is not in the dhcp server’s ip pool range.
Use a subnet on the flat’s interface that would not interfere with the subnets in the flats, like 10.10.0.1/24.
You mean connect the routers WAN port to my router or switch right?
What if the WAN port is being used for internet purposes?
I mean each flats localnet is already connected to the internet
Maybe I should a router anyway in this case right?
If you are not providing the internet connection for all the flats, you have a real problem with the setup I suggested.
If the flats have their own connections, then you will need to allow access to the camera from the internet, and the flats will need to connect to the RB1100 from the internet, and you need to route the public ip and camera port on the RB1100 to the camera.
I have internet in the Flats but not in the Camera
There is nothing like physical post forwarding or maybe protection?
Do you understand the acronym “SOL”? That means “no”. If the flats provide their own internet connection, and the RB1100 has no internet connection, then that scenario is out of the question.
You might consider using a wireless interface on the RB1100 that the flats can connect to in order to see the camera. That would be the easiest and least expensive of the alternatives. A RB411 could provide that type connection.
It is really SOL then
I was told that the RB1100 has such a thing
I can see behind it 8 ports. Can these ports route incoming to one port and never allow communication between each others?
The RB1100 has a lot of horsepower, but it has limitations, as do the other Mikrotik routers. I’m not certain what your original plan was that led you to select the RB1100. Were you planning on connecting to each flat’s localnet with your RB1100? Were you planning on wiring the entire building to access the individual routers?
Yes
Wire every flat to my RB1100
How many flats? Do you plan on installing another router in each flat? Can you modify each router’s localnet ip/subnet?
I have 8 flats
Each has its own default IP network with a router
FLAT > ROUTER < INTERNET
|
RB1100
|
CAMERA
So the router is a random device people usually get from ISP
I may add another router which its wan connected to RB1100 and LAN to Flat Router