Configuring NAT

Lab 29: Configuring Access Lists, Named Access Lists, and EIGRP Route Filters ”Part I

Practical Scenario

This chapter has stressed the importance of understanding access lists in binary. This exercise underscores this fact. In the field, you will want to make your access lists as small and efficient as possible.

Lab Exercise

The State Patrol and the County Sheriff use a national fingerprinting system at FBI headquarters. Because of the enormous growth in access and use of the system, the FBI wants to cut down on the number of networks that it can see and reach. The bureau has implemented a policy that they will route only to the even subnets for the State Patrol locations and only to the odd subnets for the County Sheriff locations. Because the State Patrol and the County Sheriff have overlapping subnets, extreme care must be taken when implementing this policy. Use the following parameters as your design guidelines:

• EIGRP is the routing protocol for this entire network. The autonomous System ID is 2001.

• Control routing updates so that the FBI router routes receive only even subnets from the State Patrol router and odd subnets from the County Sheriff router.

• The two clouds represent IP networks that the router is attached to. These clouds will be simulated by creating a route generator.

• Use named access lists.

Lab Objectives

• Configure the network as depicted in Figure 14-6. Use EIGRP as the routing protocol.

  Figure 14-6. National Fingerprinting System ”WAN Access

  

• Allow only routing updates in which the subnet is an even number to be advertised from the state_patrol router. Allow only routing updates in which the subnet is an odd number to be advertised from the county_sheriff router.

• Construct your access list with as few lines as possible.

• Check the network by issuing a trace from the fbi_hq router to the addresses 150.100.2.1, which should go to the state_patrol router. Also verify proper route advertisement by observing what routers report what routes.

Equipment Needed

• Three Cisco routers. The routers should be connected through V.35 back-to-back cables or in a similar manner.

• One LAN segment, provided through hub or switch.

Physical Layout and Prestaging

• Connect the hubs and serial cables to the routers, as shown in Figure 14-6.

• Simulate a LAN segment, as shown in Figure 14-6.

• Configure route generators on the state_patrol and county_sheriff routers. Do this by configuring 10 loopback addresses on the routers; use the same range for both routers ”150.100.1.0/24 through 150.100.10.0/24.

• Use EIGRP as the routing protocol.