Troubleshooting Exercises

1:	In the first offset list example, the access list in Barney is changed from access-list 5 permit 10.33.32.0 0.0.0.0 to access-list 5 deny 10.33.32.0 0.0.0.0 access-list 5 permit any What is the result?
2:	Figure 5.20 shows an internetwork in which the IP address masks on one router have been misconfigured. Figures 5.21 through 5.23 show the routing tables of RTA, RTB, and RTC, respectively. Based on what you know about the way RIP advertises and receives updates, explain each entry in RTB's routing table. Explain why RTB's entry for subnet 172.16.26.0 indicates a 32-bit mask. If any entries are missing in any of the routing tables, explain why. Figure 5.20. The internetwork for Troubleshooting Exercises 2 and 3. Figure 5.21. The routing table of RTA in Figure 5.20. Figure 5.22. The routing table of RTB in Figure 5.20. Figure 5.23. The routing table of RTC in Figure 5.20.
3:	Users on subnet 172.16.18.0/23 in Figure 5.20 are complaining that connectivity to subnet 172.16.26.0/23 is intermittent—sometimes it can be reached, sometimes it can't. (The bad subnet masks of RTB have been corrected.) A first examination of the routing tables of RTC and RTD (Figure 5.24) seems to show no problems. All subnets are in both tables. Yet a minute or so later, RTC shows subnet 172.16.26.0/23 to be unreachable (figure 5.25), whereas RTD still shows all subnets. A few minutes after that, the subnet is back in RTC's routing table (Figure 5.26). In each of the three figures, the routing table of RTD shows no change. A careful examination of the routing tables in Figures 5.24 through 5.26 will reveal the problem. What is it? Figure 5.24. The routing tables of RTC and RTD in figure 5.20 Figure 5.25. The routing tables of RTC and RTD ,examined approximately 60 seconds after figure 5.24 Figure 5.26. The routing tables of RTC and RTd,examined approximately 120 seconds after figure 5.25