Configuring Identity Application clustering to use TCP

As I can see from this post  IDPApps4.8.x-Configuring Permission Clustering to Use TCP  I now know what does the port_range mean (if the default port is 1000 and the range is 0 there are no additional ports, the port range number indicates the number of extra ports, so if that number is five that would mean there are 6 ports: 1000,1001,1002,1003,1004,1005). 

What I am speculating now is that on several pages of the documentation it is mentioned that IA nodes should be in the same subnet but I am speculating from documentation (https://www.netiq.com/documentation/identity-manager-48/identity_apps_admin/data/configuring-identity-applications-472-clustering-to-use-tcp-or-udp.html) this is a requirement only for clusters using UDP not TCP.

Can anyone confirm this (we do not have nodes in the same subnet if our cluster uses TCP)? Any other tips regarding clustered configuration will be appreciated.