Merge two subnets

RouterOS General
1

Dear

I need merge two subnets.

First subnet is on my port eth2 dhcp from mikrotik 192.168.201.0 / 24
Second is eth3 simuliation workstation to other subnet 10.3.20.11 / 24 gw:10.3.20.1

In this second subnet is work webserver on IP 10.56.81.141

I have to access from first subnet to this IP 10.56.81.141 from second subnets.

Please how can I make this

2

The Mikrotik is a router, it will automatically route between connected subnets without you needing to do anything, unless it is explicitly forbidden in your firewall rules.

3

My FW is clear… Router is brand new and its not work I dont know why

4

If you have access to the upstream routers, you can route the traffic.

If you don’t have access to the upstream routers, I would look at NAT for the 192.168.201.X subnet.

5

If you must connect a host onto a network using the wrong IP address
(it is 10000x much better to simply configure things normal than to make strange work-arounds)
then here is what to do:

If you know what IP the server is configured to use for default GW, add that IP address to the same interface of Mikrotik.
(e.g. 10.56.81.1/24?) You can add as many IP addresses to one interface as you wish.

As Feklar says, Mikrotik should just forward packets between networks so if you add this address, it should work so long as you do not have NAT rules or filter rules to stop it.

You could also configure the interface for proxy-arp, and create a static route to 10.56.81.141/32 next hop = ether2 (or whichever physical interface is correct)