IP addresses
The TCP/IP protocol suite uses an Internet address, or IP address, to identify each network interface on the network. Devices can have more that one interface connected to the network. Each interface must have a unique IP address that identifies that interface. In our earlier conversations we examined MAC addressing and how layer two capable devices we able to utilize the MAC address to route packets to the desired destination. MAC address switching used layer …show more content…
This organization handles requests for new address space allocations and keeps track of who has been assigned which blocks of address space. They also handle complaints and provide governance.
As a result of rapid expansion of the Internet and the growth of the number of hosts on that network, the available addresses in the space provided by Internet Protocol version four (IPv4) has run out. As a result a newer IPv6 protocol is being adopted slowly across the Internet.
Flexibility and Address Space Conservation
Companies and organizations like Hampshire College needed a way to quickly acquire new flexible address spaces that do not consume already scare address space resources. These groups started to take advantage of private, non-Internet routable address blocks provided …show more content…
Hampshire College for example was able to place layer three capable devices at the head-end wiring closet of every major building and effectively create highly controllable sub networks. This allows the College to route traffic to different ISP’s based on network ID addressing or do things like control access to certain networks with access control lists.
This design is possible using public addressing, but the ability to quickly roll out experimental address spaces, for testing is a valuable function made possible by private addresses.
NAT
If this addressing is private and publicly un-routable, then how do we get traffic across the Internet?
We can use a method called Network Address Translation to assign routable addresses to non-routable addressed traffic. Simply put, there is a bucket of routable addresses available for use by data packets that are exiting the router or firewall. The packet gets assigned a routable address as it leaves and it drops off that address when it returns. Routers keep track of these pairings in a way that is similar to the MAC address table