ICTNWK506: Topic learning guide: NAT Preparation: Watch the YouTube lecture "How Network Address Translation Works" https://www.youtube.com/watch?v=QBqPzHEDzvo Read Cisco's IOS NAT document white paper https://www.cisco.com/en/US/technologies/tk648/tk361/tk438/technologies_white_paper09186a0080 091cb9.pdf Read Cisco's "NAT FAQ" http://www.cisco.com/c/en/us/support/docs/ip/network-address- translation- nat/26704-nat- faq-00.html Watch the YouTube lecture "Setup NAT for the Cisco CCNA w/ Packet Tracer" (3 parts) https://www.youtube.com/watch?v=1G_vYlXyPLI Test your understanding You should now be able to answer the following short answer questions. 1. What are two advantages of using NAT? Security – hides private addresses; address conservation – private addresses need only be unique across the corporate network, not the Internet as a whole 2. What are the minimum number of interfaces that need to be configured on a router to support NAT? Two – at least one interface on the "NAT inside" network, and at least one interface on the "NAT outside" network 3. What is the difference between a public IP address and a private IP address? A public IP address can be accessed via the Internet and is globally unique. A private IP address need only be unique on your network, and is not directly accessible via the Internet. 4. What is the RFC that defines NAT functionality? RFC1631 5. Give an example of a TCP/IP network id (in the format a.b.c.d) that is typically used for private networks 192.168.0.0 6. T or F? NAT translation takes place after routing for outgoing (i.e. inside to outside) packets True 7. What is the difference between static and dynamic address translation in NAT? Static address translation is used to map one local address to one global address. Dynamic address translation maps a pool of local addresses to a pool of dynamic addresses. 8. If I wanted a particular local address to always have the same global address when it was mapped by NAT, what type of address translation would I use? Static 9. What is the Cisco IOS command to show define a pool of NAT addresses for translation? Ip nat pool … 10. What is the Cisco IOS command to 'mark' a router interface so packets are subjected to NAT processing? ip nat { inside | outside } Lab Complete the lab as shown in parts 2 and 3 of the "Setup NAT for the Cisco CCNA w/ Packet Tracer" (see link above to part 1; parts 2 and 3 immediately follow). Note: to complete this lab, you may need to add a serial port to the two routers you add to the network diagram (the routers may have serial ports disabled by default). What this requires you to do is to simulate the adding of an extra interface card to each of your routers (an interface card in Cisco terminology is a card that makes more ports available to the router, such as serial, fast Ethernet, Frame Relay etc). In this case the interface card you want to add is the WIC-IT interface card. Read the link below to see how it is done (you 'drag and srop' the interface card to a vacant slot on the router After you have added the interface card, a serial port should now appear in the list of interfaces) http://sherihansliit.blogspot.com.au/2012/12/how-to- add-serial- ports-to- cisco.html Save your work as Lab2, so you can demonstrate it later.