DIAGRAMAS DE PROCESOS DE LAS DIFERENTES PIEZAS

Before you install RIP, you should ensure that you have two network cards in and functioning, and that you have enabled IP forwarding. To install RIP, follow these steps:

1. Open the Network dialog box.

2. Select the Services tab, and then choose Add. 3. Select RIP for TCP/IP networks, and then click OK. 4. Close the Network dialog box.

5. Restart your system.

As a final note, you can install RIP on your NT systems that do not act as routers. This enables you to view the routes being broadcast by other RIP enabled routers only. This type of system does not broadcast because it does not have any networks to advertise, and is known as a Silent RIP Router. Its only purpose is to enable you to view the networks that your routers have found.

Objective

Summary

This chapter has covered the basics of routing and has looked at both dynamic and static routing. NT can act as either type of router, and you have seen both in this chapter. This chapter also discussed RIP routing and what that protocol adds to NT. This chapter completes an overview of the TCP protocol started in Chapter 1. The rest of this text looks at the services available in NT and what they can be used for.

Test Yourself

1. What is a router?

2. What is the difference between a router and a bridge? 3. Describe the two types of routing?

4. What conditions must be met to allow NT to act as a router? 5. Can Windows NT act as a dynamic router?

6. How often does RIP broadcast? What does it broadcast? 7. How many hops can a routing table have for using RIP? 8. Can you install RIP on a computer with only one network card? The next few questions all relate to figure 7.3.

Figure 7.3

A sample network.

9. Given that the network shown uses static routing, what commands should be given at each router if the subnet mask is 255.255.240.0?

10. What are all the routes in router A?

11. What default gateway should be assigned for hosts on 160.16.80.0 who talk primarily to hosts on 160.16.64.0?

12. Can the default gateway setting be used on this network to handle all routing? If so, what could the default gateways be set to?

13. Ignoring networks 160.16.16.0 and 160.16.32.0 and router A, the network is set up with routing based on default gateways where B defaults to D which defaults to C which defaults back to B. For each of the three networks (160.16.48.0, 160.16.64.0, and 160.16.80.0), what would be reachable if the link between router D and 160.16.80.0 were to go down?

14. What metric would be reported in the routing table of router A for the network 160.16.80.0?

15. If RIP was installed on this network, how many routers would exist for network 160.16.64.0 to reach 160.16.16.0?

Test Yourself Answers

1. A router is a physical device that connects to two or more networks and moves packets between them.

2. A bridge is an active device that scans traffic on both networks to which it is connected, and moves packets back and forth based on the hosts it knows to be on each side. Routers wait for traffic sent directly to them, and send the informa- tion to other networks based on a routing table.

3. The two types of routing are as follows:

◆ Static. Does not exchange information with other routers; it uses only its internal routing table

◆ Dynamic. Learns about other networks automatically, using one of several routing protocols such as Routing Internet Protocol or Open Shortest Path First.

4. The system must have two network cards installed, each of which requires an IP address that is valid for the subnet it is on. Then you need to check Enable IP Forwarding on the Routing tab of the TCP/IP Configuration dialog box.

5. Windows NT 4 ships with RIP routing. To install RIP routing, go to the Services tab of the Network dialog box and choose Add. RIP for Internet Protocol is listed.

6. The RIP protocol broadcasts the routing table of a RIP-enabled router every 30 seconds.

7. The furthest network can be 16 networks away or 15 hops. The biggest metric, therefore, is 15.

8. A system that uses RIP with only one card does not broadcast any routes. There- fore it is called a Silent RIP Router.

9. The commands are as follows:

Router A

ROUTE -P ADD 160.16.64.0 MASK 255.255.240.0 160.16.48.2 ROUTE -P ADD 160.16.80.0 MASK 255.255.240.0 160.16.48.3

Router B

ROUTE -P ADD 160.16.16.0 MASK 255.255.240.0 160.16.48.1 ROUTE -P ADD 160.16.32.0 MASK 255.255.240.0 160.16.48.1 ROUTE -P ADD 160.16.80.0 MASK 255.255.240.0 160.16.64.2 ROUTE -P ADD 160.16.80.0 MASK 255.255.240.0 160.16.48.3

Router C

ROUTE -P ADD 160.16.16.0 MASK 255.255.240.0 160.16.48.1 ROUTE -P ADD 160.16.32.0 MASK 255.255.240.0 160.16.48.1 ROUTE -P ADD 160.16.64.0 MASK 255.255.240.0 160.16.80.2 ROUTE -P ADD 160.16.64.0 MASK 255.255.240.0 160.16.48.2

Router D

ROUTE -P ADD 160.16.16.0 MASK 255.255.240.0 160.16.64.1 ROUTE -P ADD 160.16.16.0 MASK 255.255.240.0 160.16.80.1 ROUTE -P ADD 160.16.32.0 MASK 255.255.240.0 160.16.64.1 ROUTE -P ADD 160.16.32.0 MASK 255.255.240.0 160.16.80.1 ROUTE -P ADD 160.16.48.0 MASK 255.255.240.0 160.16.64.1 ROUTE -P ADD 160.16.48.0 MASK 255.255.240.0 160.16.80.1

10. The routes are as follows: 160.16.16.0 160.16.16.1 160.16.32.0 160.16.32.0 160.16.48.0 160.16.48.1 160.16.64.0 160.16.48.2 160.16.80.0 160.16.48.3 11. The gateway should be 160.16.80.2.

12. It is possible to use a default gateway to route on this network. You can set the gateways one of two ways: They could go A to B to D to C to A, or A to C to D to B to A.

13. The following will be true:

160.16.48.0 could see 160.16.64.0 through router B, and 160.16.80.0 through router C.

160.16.64.0 could see 160.16.48.0 through router B, but couldn’t see 160.16.80.0. 160.16.80.0 could see 160.16.48.0 through router C, and could send only to 160.16.64.0 through router C and B. There would be no response, however, because the response must come through router D.

14. The metric would be 2, one hop for router A and one for router C.

15. Two routes would be available. Packets could be sent to router B with a metric of 2, or to router D with a metric of 3.

PART II