Trabaja De Laboratoria a

Lab 1.1.4a Configuring NAT



Objective

• Configure a router to use network address translation (NAT) to convert internal IP addresses, typically private addresses, into outside public addresses.

Background/Preparation

An ISP has allocated a company the public classless interdomain routing (CIDR) IP address
199.99.9.32/27. This is equivalent to 30 public IP addresses. Since thecompany has an internal requirement for more than 30 addresses, the IT manager has decided to implement NAT. The addresses 199.99.9.33 – 199.99.9.39 for static allocation and 199.99.9.40 – 199.99.9.62 for dynamic allocation. Routing will be done between the ISP and the gateway router used by the company. A static route will be used between the ISP and gateway routers and a default route will be usedbetween the gateway router and the ISP. The ISP connection to the Internet will be represented by a loopback address on the ISP router.

Cable a network similar to the one in the diagram above. Any router that meets the interface requirements displayed on the above diagram may be used. This includes the following and any of their possible combinations:

• 800 series routers

• 1600 seriesrouters

• 1700 series routers

• 2500 series routers

• 2600 series routers

Please refer to the chart at the end of the lab to correctly identify the interface identifiers to be used based on the equipment in the lab. The configuration output used in this lab is produced from 1721 series routers. Any other router used may produce slightly different output. Conduct the followingsteps on each router unless specifically instructed otherwise.

Start a HyperTerminal session.

Note: Refer to the erase and reload instructions at the end of this lab. Perform those steps on all routers in this lab assignment before continuing.

Step 1 Configure the routers

Configure all of the following according to the chart:

• The hostname

• The console password

• The virtualterminal password

• The enable secret password

• The interfaces

If problems occur during this configuration, refer to the configuration reference sheet at the end of this lab for help.

Step 2 Save the configuration

At the privileged EXEC mode prompt, on both routers, type the command copy running-config startup-config.

Step 3 Configure the hosts with the proper IP address,subnet mask, and default gateway

Each workstation should be able to ping the attached router. If the ping was not successful, troubleshoot as necessary. Check and verify that the workstation has been assigned a specific IP address and default gateway. If running Windows 98, check using Start > Run > winipcfg. If running Windows 2000 or higher, check using ipconfig in a DOS window.

Step 4 Verifythat the network is functioning

a. From the attached hosts, ping the FastEthernet interface of the default gateway router. b. Was the ping from the first host successful? YES
c. Was the ping from the second host successful? YES

d. If the answer is no for either question, troubleshoot the router and host configurations to find the error. Ping again until they are both successful.Step 5 Create a static route

a. Create a static route from the ISP to the Gateway router. Addresses 199.99.9.32/27 have been allocated for Internet access outside of the company. Use the ip route command to create the static route.

ISP(config)#ip route 199.99.9.32 255.255.255.224 200.2.2.18

b. Is the static route in the routing table? YES

c. What command checks the routingtable contents? #SHOW IP ROUTE

d. If the route was not in the routing table, give one reason why this might be so?

Posiblemente puede que la carga de la tabla enrutameinto no se alla cargado a un, esta tablas suelen tardar un poco de tiempo para actualizar su sistema

Step 6 Create a default route

a. From the Gateway router to the ISP router, create a static route to network...