You are the network administrator at ComputerNetworkingNotes.com.
Your company hire a new employee and give him a pc 10.0.0.3. your company's critical record remain in 40.0.0.3. so you are asked to block the access of 40.0.0.3 from 10.0.0.3. while 10.0.0.3 must be able connect with other computers of network to perfom his task.