Is there a way to disable NAT in router mode? I have three different routers (LinkSys, Huawei, and Tp-link) sitting on the main network (192.168.0.0/24) and each routing to its individual sub-net. Linksys (192.168.1.0/24), Huawei (192.168.2.0/24), Tp-link (192.168.3.0/24). All the pcs under the sub-nets .1 and .2 can talk to one another but not for pc under .3 sub-net. Both Linksys and Huawei routers have features that allow disabling of NAT, but not Tp-Link. 

Is there any way I can disable NAT or is there a way around this issue?

Thank you for any advice.