| 1: | Router R4 has two working Ethernet interfaces, and each interface has been configured with an IP address. What is the least number of routes that R4 should have in its routing table, and why? |
| A1: | Answer: R4 should have two routes, one for each directly connected subnet. |
| 2: | Router R4 has a working Ethernet1 interface whose IP address is 10.10.10.10. The subnet number of the subnet attached to that interface is 10.10.10.0, with all hosts that share the first 3 octets of 10.10.10 in the same subnet. List the routing table entry that R4 will place in its routing table for this route, including the destination, outgoing interface, and next-hop router fields. |
| A2: | Answer: The route will list 10.10.10.0 as the subnet, Ethernet1 as the outgoing interface, and nothing as the next-hop router. For directly connected routes, no other router is needed to reach that subnet, so a next-hop router is unnecessary. |
| 3: | Referring to Figure 12-8, list the three parts of the IP route that could be statically added to R1's configuration so that it could forward packets to the web server. Include the destination, outgoing interface, and next-hop router as appropriate. Figure 12-8. Figure Referenced in Chapter 12 Review Questions 
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| A3: | Answer: The route will list 173.18.13.0 as the destination subnet, Ethernet2 as the outgoing interface, and 173.18.12.43 (R2) as the next-hop router. |
| 4: | Referring to Figure 12-8, list the three parts of the IP route that R1 would learn from R2 using a routing protocol. Include the destination, outgoing interface, and next-hop router as appropriate. |
| A4: | Answer: This route would be identical to the route that was statically defined in answer to question 3. The route will list 173.18.13.0 as the destination subnet, Ethernet2 as the outgoing interface, and 173.18.12.43 (R2) as the next-hop router. |
| 5: | Referring to Figure 12-8, list the three parts of the IP route that R2 would learn from R1 in the figure. Include the destination, outgoing interface, and next-hop router as appropriate. |
| A5: | Answer: The route will list 173.18.11.0 as the destination subnet, Ethernet1 as the outgoing interface, and 173.18.12.42 (R1) as the next-hop router. |
| 6: | What is the primary purpose for using a routing protocol? |
| A6: | Answer: Routing protocols enable routers to learn the routes to all the networks and subnets in an internetwork. |
| 7: | What is a routing update? |
| A7: | Answer: A routing update is a message, as defined by a routing protocol, that another router sends to advertise routes. |
| 8: | What two routing protocols are the most popular ones used today inside a single company? |
| A8: | Answer: EIGRP and OSPF |
| 9: | What routing protocol is most often used to exchange routing information between an ISP and its customers (exterior routing protocol)? |
| A9: | Answer: BGP |
