4A.A small office wants to design a LAN to address it's new business need. The office already have an IP address from an Internet Service Provider and compelled to use the same address as service provider expressed it's inability to give new IP addresses in the range of the older one as all the addresses in that range is already in use. Give a solution that helps all the devices in the LAN could interact with external world with only one IP address. Explain the working of your solution with necessary diagrams that demonstrate the simultaneous communication of at least two hosts in the LAN with external world. (4M)