Hello i'm currently I have my chain running inside my virtual machine (with Ubuntu 16.04) and my PC (running Windows 10). NodeJS is running a server which i can access from http://192.168.0.108:3000/. 
Metamask running on firefox inside the VM can actually connect to the network.
Have tried what this post suggests( MetaMask and Access Ethereum Private Chain from other PC in the same network (for test) ) but had no luck so far.
This is my starting node commandgeth --datadir ~/eth-dev/ --identity 'nodo maquina local' --verbosity 4 --ipcdisable --rpc --port 30304 --rpccorsdomain "*" --nodiscover --syncmode "full" --networkid 7051872 --targetgaslimit 16233158 console
[Ethereum] How to connect metamask private network node on VM
go-ethereummetamasknodes
Best Answer
Force the port 8545 to rpc, e.g.
geth --datadir ~/eth-dev/ --identity 'nodo maquina local' --verbosity 4 --ipcdisable --rpc --rpcport "8545" --rpccorsdomain "*" --nodiscover --syncmode "full" --networkid 7051872 --targetgaslimit 16233158 console