Mikrotik. 4 subnets. How to do it right?

Question

Mikrotik

Good day !
The task I do not think is simple (but for me, as far from this topic, it is very difficult)
There is a mikrotik.
There is internet.
There is a LAN network 192.168.80.0/24
We must also add 3 subnets so that they do not see each other, but can exchange files via NAS (exchanger, connected as a network drive) and have the Internet.
NAS is located at 192.168.80.28
Internet (port #1)
LAN 192.168.80.0/24 (port 2)
1st subnet 192.168.90.0/27 (port #3)
2nd subnet 192.168.100.0/27 (port #4)
3rd subnet 192.168.110.0/27 (port #5)
Please help.

Answer 1

With the addition of subnets, I hope you can handle it. And the restriction can be done like this.
/ip firewall address-list add address=192.168.90.0/27 list=privatelans
/ip firewall address-list add address=192.168.100.0/27 list=privatelans
/ip firewall address-list add address=192.168.110.0/27 list= privatelans
/ip firewall filter add action=reject chain=forward src-address-list=privatelans dst-address-list=privatelans
The first three commands will create an address list with isolated subnets. The fourth command will add a filter rule that blocks traffic between them. It must be raised above all allowing rules. If there are no deny rules to the 192.168.80.0/24 subnet, then all three will have access to it.

Answer 2

if there are no prohibiting rules in the firewall - by default Mikrotik will allow traffic between subnets, so you need to make such rules (prohibiting) and make an exception in them in the form of a NAS

Answer 3

https://linkmeup.ru/blog/14.html