Configure the IP routing as in Figure 2-13, redistribute protocols to ensure full IP visibility between routers. Advertise all router networks within the appropriate routing protocol. Section 2.1: EIGRP (8 Points)
You should configure EIGRP AS30 on R1-R2-R3 and EIGRP AS20 on R6 and R8. You could just enable EIGRP with a network 10.0.0.0 statement everywhere, but as you can see in Figure 2-13, R6 and R1 do not have all their network 10 interfaces included into EIGRP. You will need to configure an inverse mask for the networks you require advertised and included in EIGRP on these routers. This is more preferable than removing the network with a distribute list later; in fact, you will find that you are not permitted to use any distribute lists in the redistribution section. Do not forget to disable auto summarization on all your routers as a matter of good practice. If you have configured this correctly as shown in Example 2-11 through Example 2-15, you have scored 2 points. Example 2-11. R1 Initial EIGRP Configurationrouter eigrp 30 passive-interface Loopback0 network 10.1.1.0 0.0.0.15 network 10.80.80.0 0.0.0.255 network 10.90.90.0 0.0.0.15 no auto-summary Example 2-12. R2 Initial EIGRP Configurationrouter eigrp 30 network 10.90.90.0 0.0.0.15 network 172.16.0.0 no auto-summary NOTE You could have configured the network statement on R2 covering the entire classfull 10.0.0.0/8 network. Example 2-13. R3 Initial EIGRP Configurationrouter eigrp 30 network 172.16.0.0 no auto-summary Example 2-14. R6 Initial EIGRP Configurationrouter eigrp 20 network 10.6.6.0 0.0.0.7 network 10.80.80.0 0.0.0.255 no auto-summary Example 2-15. R8 Initial EIGRP Configurationrouter eigrp 20 network 10.8.8.8 0.0.0.0 network 10.80.80.0 0.0.0.255 no auto-summary NOTE You could have configured the network statement on R8 covering the entire classfull 10.0.0.0/8 network.
Add the EIGRP summary statement for network 10/8 on R1 S0/0 as shown in Example 2-16. If you have configured this correctly, you have scored 1 point. Example 2-16. R1 EIGRP Summary 10/8 Configurationinterface Serial0/0 ip address 10.90.90.2 255.255.255.240 ip summary-address eigrp 30 10.0.0.0 255.0.0.0
You are not permitted to configure a default route so no statics can be redistributed. Hopefully, the previous question may have prompted you to once again use a summary route. You will find by configuring a summary route to 0/0 on R1 S0/0 that a default route will be propagated into EIGRP AS30. If you have configured this correctly as shown in Example 2-17 with the resulting 0/0 route on R2, you have scored 2 points. Example 2-17. R1 EIGRP Summary 0/0 Configuration and R2 Route Outputinterface Serial0/0 ip address 10.90.90.2 255.255.255.240 ip summary-address eigrp 30 0.0.0.0 0.0.0.0 R2#sh ip route C 172.16.0.0/16 is directly connected, FastEthernet0/0 10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks D 10.0.0.0/8 [90/2172416] via 10.90.90.2, 00:16:43, Serial0/0 C 10.90.90.0/28 is directly connected, Serial0/0 D* 0.0.0.0/0 [90/2172416] via 10.90.90.2, 00:16:43, Serial0/0
You will find that R8 interface Lo0 has a /32 mask and, hence, will be advertised as a host route. You will need to perform further EIGRP summarization to expand the network range. You can expand the range using a sensible mask of your choice. If you have configured this correctly as shown in Example 2-18, you have scored 1 point. Example 2-18. R8 EIGRP Summary Lo0 Configurationinterface FastEthernet0/0 ip address 10.80.80.3 255.255.255.0 ip summary-address eigrp 20 10.8.8.0 255.255.255.240
This is not a difficult question, but it is one of those that will eat into your time so ensure you accurately configure your routers; otherwise, you will end up wasting time troubleshooting your own errors. You will need to configure MD5 authentication, which is in fact the only type available across all your EIGRP enabled interfaces as shown in Example 2-19 through Example 2-23. Bear in mind that even on networks with no neighbors at this point in time, you should still have the authentication statement. The obvious exception to this rule is loopback interfaces. If you have configured this correctly, you have scored 2 points. NOTE Consider creating a text file for repetitive configuration such as this and pasting to your routers to save time. Example 2-19. R1 EIGRP Authentication Configurationkey chain EIGRP-MD5 key 1 key-string anna ! interface FastEthernet0/0 ip authentication mode eigrp 30 md5 ip authentication key-chain eigrp 30 EIGRP-MD5 ! interface Serial0/0 ip authentication mode eigrp 30 md5 ip authentication key-chain eigrp 30 EIGRP-MD5 Example 2-20. R2 EIGRP Authentication Configurationkey chain EIGRP-MD5 key 1 key-string anna ! interface FastEthernet0/0 ip authentication mode eigrp 30 md5 ip authentication key-chain eigrp 30 EIGRP-MD5 ! interface Serial0/0 ip authentication mode eigrp 30 md5 ip authentication key-chain eigrp 30 EIGRP-MD5 Example 2-21. R3 EIGRP Authentication Configurationkey chain EIGRP-MD5 key 1 key-string anna ! interface FastEthernet0/0 ip authentication mode eigrp 30 md5 ip authentication key-chain eigrp 30 EIGRP-MD5 Example 2-22. R6 EIGRP Authentication Configurationkey chain EIGRP-MD5 key 1 key-string anna ! interface FastEthernet0/0 ip authentication mode eigrp 20 md5 ip authentication key-chain eigrp 20 EIGRP-MD5 Example 2-23. R8 EIGRP Authentication Configurationkey chain EIGRP-MD5 key 1 key-string anna ! interface FastEthernet0/0 ip authentication mode eigrp 20 md5 ip authentication key-chain eigrp 20 EIGRP-MD5 Section 2.2: OSPF (13 Points)
You will need to configure OSPF on R1, R4, R6, and R5 ensuring that the OSPF-only routers (R4 and R5) have their loopbacks advertised within their Ethernet assigned areas. R1 and R6 should have had their loopbacks advertised earlier within EIGRP. You will also need to configure a virtual link between R6 and R5 to extend area 0 out to R5 area 3 through area 4. Pay attention to your router IDs as you will add further loopback interfaces to your configuration, which will change the router ID, unless you manually configure your ID within OSPF as shown in the solution examples. If you have configured this correctly as shown in Example 2-24 through Example 2-27, you have scored 2 points. Example 2-24. R1 Initial OSPF Configurationrouter ospf 30 network 10.10.10.0 0.0.0.15 area 0 network 10.100.100.0 0.0.0.15 area 0 Example 2-25. R4 Initial OSPF Configurationrouter ospf 30 network 10.4.4.0 0.0.0.7 area 2 network 10.10.10.0 0.0.0.15 area 0 network 10.40.40.0 0.0.0.15 area 2 network 10.100.100.0 0.0.0.15 area 0 network 10.100.101.0 0.0.0.15 area 0 Example 2-26. R5 Initial OSPF Configurationrouter ospf 30 area 4 virtual-link 10.6.6.6 network 10.5.5.4 0.0.0.3 area 3 network 10.50.50.0 0.0.0.7 area 3 network 10.99.99.0 0.0.0.7 area 4 router-id 10.5.5.5 Example 2-27. R6 Initial OSPF Configurationrouter ospf 30 area 4 virtual-link 10.5.5.5 network 10.99.99.0 0.0.0.7 area 4 network 10.100.101.0 0.0.0.15 area 0 router-id 10.6.6.6
The earlier ATM question ensured that the ATM network would be treated as NBMA. Even if you did configure an OSPF network type, you would still require broadcast capability, which you do not have, over the ATM to multicast OSPF between routers. The question calls for you to statically define a remote neighbor, which will then enable the routers to unicast OSPF to each other and form an adjacency. If you have configured neighbor 10.99.99.1 and neighbor 10.99.99.2 on R5 and R6, respectively, you have scored 1 point. NOTE The neighbor relationship will still form if only one neighbor statement is configured on either R5 or R6. If you have configured only one statement, this is still acceptable for a full score.
As you can not advertise the network from R5 and your network requires visibility of it, you must advertise it from another router. The problem lies in that you cannot use a static route and redistribute this. The only way to achieve this is to configure a similar network on R6 and add it into either EIGRP or OSPF. You can then summarize this network out to the original mask of that configured on R5 to ensure the entire network learns about the network that is actually configured on R5 but through R6. The next step is to ensure that when traffic destined for the network on R5 reaches R6 it is forced onward to R5 instead of terminating at R6. You will need to policy route to achieve this. Your policy routing should ensure that any traffic destined to 10.200.200.1 is forwarded to R5 and it will need to be placed on R6 Fast Ethernet and virtual-template interfaces where traffic would ingress for this destination from your entire network. If you have configured this correctly as shown in Example 2-28 and Example 2-29, which also shows the resulting ping verification from R1, you have scored 5 points. Example 2-28. R5 Loopback Configurationinterface Loopback1 ip address 10.200.200.1 255.255.255.248 Example 2-29. R6 Loopback Configuration, Policy Routing, and Ping Test from R1interface Loopback1 ip address 10.200.200.5 255.255.255.252 ip ospf network point-to-point ! interface FastEthernet0/0 ip policy route-map 10.200.200.1-to-R5 ! interface Virtual-Template1 ip policy route-map 10.200.200.1-to-R5 ! router ospf 30 area 4 range 10.200.200.0 255.255.255.248 network 10.200.200.4 0.0.0.3 area 4 ! ip local policy route-map 10.200.200.1-to-R5 ! access-list 100 permit ip any host 10.200.200.1 ! route-map 10.200.200.1-to-R5 permit 10 match ip address 100 set ip next-hop 10.99.99.2 R5#debug ip icmp ICMP packet debugging is on R1#ping 10.200.200.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.200.200.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/8/12 ms R5# 00:45:46: ICMP: echo reply sent, src 10.200.200.1, dst 10.100.100.1 00:45:46: ICMP: echo reply sent, src 10.200.200.1, dst 10.100.100.1 00:45:46: ICMP: echo reply sent, src 10.200.200.1, dst 10.100.100.1 00:45:46: ICMP: echo reply sent, src 10.200.200.1, dst 10.100.100.1 00:45:46: ICMP: echo reply sent, src 10.200.200.1, dst 10.100.100.1 NOTE R6 uses the command ip ospf network point-to-point under interface Loopack0 to ensure the network is not advertised as a host route to the OSPF domain.
You should recall that an OSPF stub area with the key word no-summary will restrict the LSA types to 1 and 2 with the default route being advertised automatically with an LSA type 3. R4 OSPF process should be configured with area 2 stub no-summary. If you have configured this correctly, you have scored 2 points.
This is another time-consuming question that will require OSPF updates to be authenticated on a per-interface basis using MD5 encryption. Remember to also add authentication to your virtual link. If you have configured this correctly as in Example 2-30 through Example 2-33, you have scored 2 points. Example 2-30. R1 OSPF Authentication Configurationinterface BRI0/0 ip ospf message-digest-key 1 md5 james ! interface Virtual-Template1 ip ospf message-digest-key 1 md5 james ! router ospf 30 area 0 authentication message-digest Example 2-31. R4 OSPF Authentication Configurationinterface FastEthernet0/0 ip ospf message-digest-key 1 md5 james ! interface BRI0/0 ip ospf message-digest-key 1 md5 james ! interface Virtual-Template1 ip ospf message-digest-key 1 md5 james ! interface Virtual-Template2 ip ospf message-digest-key 1 md5 james ! router ospf 30 log-adjacency-changes area 0 authentication message-digest area 2 authentication message-digest Example 2-32. R5 OSPF Authentication Configurationinterface FastEthernet0/0 ip ospf message-digest-key 1 md5 james ! interface ATM3/0 ip address 10.99.99.2 255.255.255.248 ip ospf message-digest-key 1 md5 james ! router ospf 30 log-adjacency-changes area 0 authentication message-digest area 3 authentication message-digest area 4 authentication message-digest area 4 virtual-link 10.6.6.6 message-digest-key 1 md5 james Example 2-33. R6 OSPF Authentication Configurationinterface ATM1/0 ip ospf message-digest-key 1 md5 james ! interface Virtual-Template1 ip ospf message-digest-key 1 md5 james ! router ospf 30 area 0 authentication message-digest area 4 authentication message-digest area 4 virtual-link 10.5.5.5 message-digest-key 1 md5 james
You will need to configure your loopback interfaces on R4, R5, and R6, which are advertised within OSPF with ip ospf-network point-to-point statements to ensure they are advertised with the correct mask as opposed to /32 host routes to your network. You will also need to configure your Virtual-Template interfaces on R1 and R4 with the command no peer neighbor-route to remove the /32 host routes that are added to the routing table when the PPP links becomes active. These would then be propagated into your OSPF domain. If you have configured this correctly, you have scored 1 point. Section 2.3: Redistribution (7 Points)
You are not being requested to perform mutual redistribution here so you simply redistribute EIGRP into OSPF on R1. The default route will not be propagated by default as R1 would require the default-information originate command to achieve this. You need to remember that OSPF by default redistributes classfull networks so you will need the keyword subnets in your configuration along with your specified default metric. If you have configured this correctly as shown in Example 2-34, you have scored 2 points. Example 2-34. R1 EIGRP AS30 Initial Redistribution Configurationrouter ospf 30 redistribute eigrp 30 subnets default-metric 4000
Usually, you would selectively redistribute routes based on a distribute list or use a route matching the EIGRP routes from OSPF, which would appear as External routes; as you cannot do this, you must attach an identification to the EIGRP AS20 routes as they ingress the OSPF network. By tagging the EIGRP routes on R1 as they are redistributed into OSPF, you will be able to use a route map on R6 and match all the tagged routes searching for the value you entered on R1. You can then allow the tagged routes to be redistributed into EIGRP AS30. Example 2-35 shows how to tag the EIGRP AS30 routes on R1; Example 2-36 shows how the tagged routes are redistributed into EIGRP AS30 on R6 with the resulting topology shown with the redistributed tagged routes. If you have configured this correctly, you have scored 4 points. Example 2-35. R1 EIGRP AS30 Redistribution with Tagging Configurationrouter ospf 30 redistribute eigrp 30 subnets tag 7942 Example 2-36. R6 EIGRP AS30 Redistribution with Tagging Configuration and Confirmationrouter eigrp 20 redistribute ospf 30 route-map ospf-7942-eigrp20 default-metric 1000 10 255 1 1500 ! route-map ospf-7942-eigrp20 permit 10 match tag 7942 R1#sh ip ospf database self-originate OSPF Router with ID (10.1.1.1) (Process ID 30) Router Link States (Area 0) Link ID ADV Router Age Seq# Checksum Link count 10.1.1.1 10.1.1.1 243 0x80000005 0x002FD9 3 Type-5 AS External Link States Link ID ADV Router Age Seq# Checksum Tag 10.0.0.0 10.1.1.1 227 0x80000002 0x007651 7942 10.1.1.0 10.1.1.1 227 0x80000002 0x0005CF 7942 10.80.80.0 10.1.1.1 227 0x80000002 0x003FE7 7942 10.90.90.0 10.1.1.1 227 0x80000002 0x00FD24 7942 172.16.0.0 10.1.1.1 227 0x80000002 0x0073A1 7942 R6#sh ip eigrp topology IP-EIGRP Topology Table for AS(20)/ID(10.6.6.6) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.0.0.0/8, 1 successors, FD is 2562560, tag is 7942 via Redistributed (2562560/0) P 10.1.1.0/28, 1 successors, FD is 2562560, tag is 7942 via Redistributed (2562560/0) P 10.90.90.0/28, 1 successors, FD is 2562560, tag is 7942 via Redistributed (2562560/0) P 10.8.8.0/28, 1 successors, FD is 156160 via 10.80.80.3 (156160/128256), FastEthernet0/0 P 10.80.80.0/24, 1 successors, FD is 28160 via Connected, FastEthernet0/0 P 10.6.6.0/29, 1 successors, FD is 128256 via Connected, Loopback0 P 172.16.0.0/16, 1 successors, FD is 2562560, tag is 7942 via Redistributed (2562560/0) NOTE R6 does not show network 10.80.80.0/24 as a tagged network learnt from OSPF via EIGRP AS30 because this is a connected interface.
Simply redistribute the EIGRP AS20 routes into OSPF on R6; this will ensure that the OSPF network learns about the networks advertised by R8. EIGRP AS20 does not require any tagging as R1 is not performing mutual redistribution. R1 will learn EIGRP AS20 routes via OSPF; R2 and R3 have a network 10/8 summary to R1 so they will have reach capability of EIGRP AS20 through R1. Remember to use the subnets keyword and default-metric as before or add the associated metrics to the redistribute statement. If you have configured this correctly as in Example 2-37, you have scored 1 point. Example 2-37. R6 EIGRP AS20 Redistribution Configurationrouter ospf 30 redistribute eigrp 20 subnets default-metric 4000 |