Computer A is part of a network of 4 pc’s with internet access. Computer B is part of another network of 2 pc’s but no internet access. We do not want computer B to have internet access due to virus, etc. Can I use an RJ45 cable to connect computer A to B? Can the virus pass from A to B in case of an infection? All pc’s are in a shelf, so running a cable is easy. Please let me know your thoughts. New to this.