access control list
an access-list is used.
A router
yes
It depends on how many interfaces of router are connected to other networks. If a router is connected to two network, it will have 2 IP addresses. In a router having 4 ports it can connect to maximum 4 networks. In this case it will have 4 IP addresses.
You can use router of G or N type and the same type wireless adapter. Of course you can use wireless N adapter with G-type router and reverse.
When applying IPv4 addresses to router interfaces on a network, you would manually configure predictable addresses. For example, the lowest or highest address of the local subnet, on each particular router interface.
They are normally the IP addresses which your computer uses to talk to your internet router/modem. They are not the same as the IP address that your router is known by on the broadband link.
Since Facebook uses a limited range of IP addresses, blocking those addresses on the router will effectively deny access to Facebook.
Your Router is assigned an IP address that is known as a public IP address then your router assigns out IP addresses that are known as local IP addresses. So the answer is yes and yes!
Sometimes a router has the option to exclude all connections apart from certain specific devices. It is those devices' MAC addresses that you will need to enter in order for the router to indentify them.
NAT in the router Implementing ipv6 would be a better option.