Question

Extra Credit Assignment

• Describe the purpose of having NAT (Network Address Translation) and PAT (Port Address Translation).
• Describe the difference between NAT (Network Address Translation) and PAT (Port Address Translation).
• Give an example for each of them.
• Describe them using images (please explain each part on the image that you use)
• Please list your reference and cite them appropriately.

Answer 1

Network Address Translation (NAT) for the first two decades of the Internet, The computers a private network connected to the internet worked this way: Get block of unique public IP addresses and assign them each computer. 1 23:138 11.2.3.139 1.2.4 L 1.2.3.137 ISP Internet Service provider . Switch 1.2.3.140 Default Gateaway 1.2.3.141 and LAN side LAN side of the default of the default gateway. Then assign IP address of ISP's router on the WAN side of the default gateway. Then tell each computer on private network the default default gateway's IP addrey. All IP addresses in this public are setup two big This are classic setup has at least problems? Security vulnerability :- Since IP addresses public, everyone can access this so-called ee private " network. grows larger could imagine, IP ) IP address exhaustion:- As the internet and faster than anyone ever could address were running out quickly. very

for outgoing traffic. To come solue these problems private IP addressing and Network Address Translation, or NAT to rescue. NAT ( Network Address Translation) NAT is a proces where router a similar network device, translate one IP address into another IP address. specifically, a router translates an internal hosts private IP address into its public IP address and it also translates its public IP address to an internal private address for incoming traffic. NAT benefits :- D NAT improves security because internet hosts IP addresses are hidden. scher private 2) NAT, together with IPVA conserves IPUT address space and thus extends its lifespan. addressing 4 types of NAT:- static NAT 2) Dynamic NAT 3) PAT ( Port Address Translation) u) Port forwarding.

192.168.100 192 192.168.1oo. I Swapping Internet LLANIWAN Router 192.168.100.53 192.168.10078 934.1.2.33 LAN WAN to figure - PAT through the router's NAT table and sent original host. The mapp oping of Internal IP address port number translate IP address and port number than enables perfect tracking of packets in and out. PAT hosts with handle many singl can IP address the TCP/IP port numbe 16 - digit value (2^16 = 65,536) some of those port numbers used for common protocols, but tens of thousands are available for PAT to work its magic. many internal since public space are