Explain why NAT is often mentioned as a solution to counteract the depletion of IP addresses on the global Internet. Which alternatives to NAT exist that address the scarcity of available IP addresses?.

What will be an ideal response?

NAT provides IP masquerading function (also known as NAPT), that allows more than one hosts in an internal network to communicate with the outside network through a single public IP address. This functionality addresses the scarcity of available IP addresses problem. A private network can be allocated any number of the class B or C IP addresses from the pool defined by RFC 1918. The NAT router can then map these IP addresses, either statically or dynamically to the global IP addresses available to itself. This way the hosts in the private network can access the public network. Therefore NAT is often mentioned as a solution to counteract the depletion of IP addresses. Other alternatives that can be used to address this problem are using CIDR. IPV6 is also an alternative to address the scarcity of IP addresses. Also there is a virtual private network (VPN) which is a group of two or more computer systems, typically connected to a private network with limited public-network access, that communicates securely over a public network. And Link Tunnel Protocols like L2 uses address translation in firewall products.