The Network Intrusion

You and your Shadowrunner Team have been hired by the government to hack into the headquarters of the Comit-Corperation to locate evidence of illegal activity. They suspect that it is kept on a single secure server but their internal network is extremely secure and the government investigation agency could not retrieve any information on it except the following:

The network is divided into 10 subnets in which each IP Address is tied to the number of nodes on it.

192.168.2.0 -> 2 Nodes
192.168.3.0 -> 3 Nodes
192.168.4.0 -> 4 Nodes
192.168.5.0 -> 5 Nodes
192.168.6.0 -> 6 Nodes
192.168.7.0 -> 7 Nodes
192.168.8.0 -> 8 Nodes
192.168.9.0 -> 9 Nodes
192.168.10.0 -> 10 Nodes
192.168.11.0 -> 11 Nodes

They know that the suspect server is on the lowest numbered subnet that can satisfy the following conditions:

Each node has exactly LAN connections to 3 other nodes in that subnet.
The only exception to this is the suspect server which has a LAN connection to only 1 node.

You can ignore any WAN connections as those just connect subnets together and are therefore irrelevent.

Also there some other complications as well:

There are no topology diagrams of the network accessible anywhere.

You only have enough time to search a single subnet before the Intrusion Detection Systems spot your unauthorized access and lockdown the entire network kicking you off.

SOLUTION:
The suspect server is on subnet 192.168.6.0

How I know if this is correct? Becuase it is the only one that satisfys the conditions stated above. We know that each node has to have exactly three LAN connections on each except one which is the server. So by graphing this out there has to at least 6 nodes for all of the conditions to be satisfied.