I have the following situation and I don't know how to ask google.
I have a cabled LAN segment, lets say 192.168.1.X. One of the nodes there is a wifi router 192.168.1.3 that creates wireless segment 192.168.2.X for some laptops.
I want to put all of the computers in the same network (192.168.1.X) and not to maintain 2 different networks (1.X and 2.X). I don't want to have a gateway or firewall between them. Is this possible? What is this mode called?
You are probably looking for "bridging". Typically, an access point will do this by default. Performing routing and firewall functionality as you describe it is an advanced configuration not every access point device would support.
You want your router to perform all the routing, not your AP. So you just need to use it as a hub instead of a router.
I would like to ask if the IPs in the network are assigned by a DHCP server or manually assigned?
I would assume that it is DHCP assigned, therefore I would suggest that you disable the DHCP assignment on the wireless AP. Leave the assignment to the DHCP server and you should not have the issue with 2 different network segment.
Hopefully this helps.