Computer Networking and Management Essay Example | Topics and Well Written Essays - 7000 words

Computer Networking and Management - Essay Example However, this is a rare event. The following illustration shows the routing and remote access procedure of the NAT service. You can see that the NAT router sits in the middle of a conversation between the public and the private machine. The packets are translated and then sent to the destination computer at the public end of the equation. The response of the turns, and the route also translates from the public network and returns the response back to the requesting client at the local end. The workstations obtain their IP addresses in the range allowed by the Internet Assigned Numbers Authority (IANA). IANA is responsible for allocating public addresses that are guaranteed to be globally unique on the Internet. However, there is an ever decreasing availability of Ipv4 addresses available as thousands and thousands of additional IP addresses are required daily. In the longer term the development of IPv6 16 byte addresses should resolve this problem. Another factor about IPv6 addresses is that they are expressed in hexadecimal notation with ':' as separators, rather than the current '.' notation of the IPv4 addressing system. The workaround available at the moment on small networks is to reuse IPv4 addresses. Workstations obtain their reusable (i.e. dynamic) IP addresses using a Dynamic Host Configuration Protocol server (DHCP). The DHCP automatically configures the IP address for every host on the network, thus ensuring that each host has a valid, unique IP address. The DHCP automatically reconfigures IP addresses on the fly, i.e. as and when hosts may or may not be present. One of the major advantages of DHCP is that it can save a network administrator many hours of tedious configuration work. DHCP allows individual computers on a TCP/IP network to obtain their configuration information. Specifically, this is their IP address from the server. The DHCP server keeps track of which IP addresses of already been assigned so that when a computer requests an IP address, the DHCP server will offer it an IP address that is not already in use. One of the advantages of an NAT is that firewalls use this method to hide the actual IP address of a host from outside world. In this situation the NAT device must use of a globally unique IP address to represent itself to the Internet. It obtains its global address for communicating with the outside world from the firewall. This firewall address is the address to which forwarded and received packet travel to and from the Internet. Because NAT uses a global IP address for its local network machines, it assists with the general problem of IPv4 addresses being allocated exponentially. The NAT device keeps track of the requesting hosts IP address. It hides this host address and provides its own firewall address to the Internet. The response is received back to the firewall address, and then the NAT router looks of this information about the original request and forwards the information back to the correct host on the internal network. Task3: A) There