Cisco CCNP 642-902 Exam 1

Ensurepass

QUESTION 1
In this question you need to redistribute between OSPF and EIGRP such that 172.16.100.1 is reachable from router R1.

R2 is an ASBR for EIGRP 100 and OSPF AREA 24
R3 is an ASBR for EIGRP 100 and OSPF AREA 34
NotE. There are TWO separate areas on TWO separate ASBRS thus you need to do redistribution on R2 and R3
R1 is ONLY in EIGRP 100, and is THE ONLY router you can ping from. R4 has a loopback interface that must be pinged from R1.
R4 is running OSPF and has redundant links to EIGRP network over R3 router.
NotE. You should ping from R1 to 172.16.100.1 network to make sure everything is working correctly.

Correct Answer:
First we need to find out 5 K-Values used for EIGRP (Bandwidth, Delay, Reliability, Load, MTU) of the s0/0/0 interface (the interface of R2 connected to R4) for redistribution:

R2#show interface s0/0/0

Write down these 5 parameters, notice that we have to divide the Delay by 10 because its metric unit is tens of microsecond. For example, we get Bandwidth=1544 Kbit, Delay=20000 us, Reliability=255, Load=1, MTU=1500 bytes then we would redistribute as follows:

R2#config terminal
R2(config)#router ospf 1
R2(config-router)# redistribute eigrp 100 metric-type 1 subnets
R2(config-router)#exit
R2(config-router)#router eigrp 100
R2(config-router)#redistribute ospf 1 metric 1544 2000 255 1 1500

(NoticE. In fact, these parameters are just used for reference and we can use other parameters with no problem. Also, a candidate said that the simulator didn’t accept the Bandwidth of 1544; in that case, we can use a lower value, like 128.)
If the delay is 20000us then we need to divide it by 10, that is 20000 / 10 = 2000)
For R3 we use the show interface fa0/0 to get 5 parameters too

R3#show interface fa0/0

For example we get Bandwidth=10000 Kbit, Delay=1000 us, Reliability=255, Load=1, MTU=1500 bytes

R3#config terminal
R3(config)#router ospf 1
R3(config-router)#redistribute eigrp 100 metric-type 1 subnets
R3(config)#exit
R3(config-router)#router eigrp 100
R3(config-router)#redistribute ospf 1 metric 10000 100 255 1 1500

QUESTION 2
Company Acan has two links which can take it to the Internet. The company policy demands that you use web traffic to be forwarded only to Frame Relay link and other traffic can go through any links that are available. Use BGP attributes to solve the requested action.

Correct Answer:
1) Create an Access list that catches the HTTP traffic:
BorderRouter#access-list 101 permit tcp any any eq www
Note that the server was not directly connected to the Border Router. There were a lot of EIGRP routes on it. In the real exam you do not know the exact IP address of the server in the EIGRP network so we have to use the source as “any” to catch all the source addresses.

2) Route map that sets the next hop address to be ISP1 and permits the rest of the traffic: BorderRouter(config)#route-map pbr permit 10
BorderRouter(config-route-map)#match ip address 101
BorderRouter(config-route-map)#set ip next-hop 10.1.101.1
BorderRouter(config-route-map)#exit
BorderRouter(config)#route-map pbr permit 20
(NoticE. the route-map pbr permit 20 line allows other traffic than HTTP to be routed. Otherwise, other traffic will be dropped)

3) Apply the route-map on the interface to the server in the EIGRP Network: BorderRouter(config-route-map)#exit
BorderRouter(config)#int fa0/0
BorderRouter(config-if)#ip policy route-map pbr
BorderRouter(config-if)#exit BorderRouter(config)#exit

4) There is a “Host for Testing”, click on this host to open a box in which there is a button named “Generate HTTP traffic”. Click on this button to generate some packets for HTTP traffic. Jump back to the BorderRouter and type the command “show route-map”.
BorderRouter#show route-map
In the output you will see the line “Policy routing matches: 9 packets…”. It means that the route- map we configured is working properly.

QUESTION 3
By increasing the first distant office, JS manufactures has extended their business. They configured the remote office router (R3) from which they can reach all Corporate subnets. In order to raise network stableness and lower the memory usage and CPU utilization to R3, JS manufactures makes use of route summarization together with the EIGRP Stub Routing feature. Another network engineer is responsible for the implementing of this solution. However, in the process of configuring EIGRP stub routing connectivity with the remote network devices off of R3 has been missing.

Presently JS has configured EIGRP on all routers in the network R2, R3, and R4. Your duty is to find and solve the connectivity failure problem with the remote office router R3. You should then configure route summarization only to the distant office router R3 to complete the task after the problem has been solved. The success of pings from R4 to the R3 LAN interface proves that the fault has been corrected and the R3
IP routing table only contains two 10.0.0.0 subnets.

Correct Answer:
Use the show runningconfig command on router R3

Notice that R3 is configured as a stub receive-only router. The receive-only keyword will restrict the router from sharing any of its routes with any other router in that EIGRP autonomous system. This keyword will also prevent any type of route from being sent. Therefore we will remove this command and replace it with the eigrp stub command:
R3#configure terminal
R3(config)#router eigrp 123
R3(config-router)#no eigrp stub receive-only
R3(config-router)#eigrp stub
R3(config-router)#end

Now R3 will send updates containing its connected and summary routes to other routers. Notice that the eigrp stub command equals to the eigrp stub connected summary because the connected and summary options are enabled by default. Next we will configure router R3 so that it has only 2 subnets of 10.0.0.0 network. Use the show ip route command on R3 to view its routing table R3#show ip route

Because we want the routing table of R3 only have 2 subnets so we have to summary sub- networks at the interface which is connected with R3, the s0/0 interface of R4. There is one interesting thing about the output of the show ip route shown abovE. the 10.2.3.0 /24, which is a directly connected network of R3. We can’t get rid of it in the routing table no matter what technique we use to summary the networks. Therefore, to make the routing table of R3 has only 2 subnets we have to summarize the other subnets into one subnet. In conclusion, we will use the ip summary-address eigrp 123 10.0.0.0 255.0.0.0 at the interface s0/0 of R4 to summary.

R4>enable
R4#configure terminal
R4(config)#interface s0/0
R4(config-if)#ip summary-address eigrp 123 10.0.0.0 255.0.0.0

Now we jump back to R3 and use the show ip route command to verify the effect, the output is shown below: (But please notice that the ip addresses and the subnet masks in your real exam might be different so you might use different ones to solve this question) Just for your information, notice that if you use another network than 10.0.0.0/8 to summary, for example, if you use the command ip summary-address eigrp 123 10.2.0.0 255.255.0.0 you will leave a /16 network in the output of the show ip route command.

But in your real exam, if you don’t see the line “10.0.0.0/8 is a summary,….Null0” then you can summary using the network 10.2.0.0/16. This summarization is better because all the pings can work well. Finally don’t forget to use the copy running-config startup-config command on routers R3 and R4 to save the configurations.

R4(config-if)#end
R4#copy running-config startup-config

QUESTION 4
OSPF is configured on routers Amani and Lynaic. Amani’s S0/0 interface and Lynaic’s S0/1 interface are in Area 0. Lynaic’s Loopback0 interface is in Area 2.

Your task is to configure the following:
Portland’s S0/0 interface in Area 1
Amani’s S0/1 interface in Area 1

Use the appropriate mask such that ONLY Portland’s S0/0 and Amnani’s S0/1 could be in Area 1. Area 1 should not receive any external or inter-area routes (except the default route).

Correct Answer:
First, we configure Portland’s S0/0 interface so that it belongs to Area 1. So, we have to find out which subnetwork the IP address 192.168.4.5/30 (the IP of interface S0/0 of Portland) belongs to. This address belongs to a subnetwork which has:
Increment: 4 (/30 = 255.255.255.252 or 1111 1111.1111 1111.1111 1111.1111 1100)
Network address: 192.168.4.4 (because 4 = 4 * 1 and 4 < 5) Broadcast address: 192.168.4.7 (because 7 = 4 + 4 - 1) (It is not necessary to find out the broadcast address but we should know it) The question requires that only Portland's S0/0 and Amani's S0/1 could be in Area 1, therefore we must use a wildcard of 0.0.0.3 (this wildcard is equivalent with a subnet mask of /30) so that there are only 2 IP addresses can participate in area 1 (they are 192.168.4.5 & 192.168.4.6). The full command we use here is network 192.168.4.4 0.0.0.3 area 1 The question also requires that "Area 1 should not receive any external or inter-area routes (except the default route)". Recall that if we don't want the router to receive external routes, we have to stop LSA Type 5. And if we don't want to receive inter-area routes, we have to stop LSA Type 3 and Type 4. Therefore we have to configure area 1 as a totally stubby area. For your information, here is the definition of a totally stubby areA. "Totally stubb area - This area does not accept summary LSAs from other areas (types 3 or 4) or external summary LSAs (Type 5). Types 3,4 and 5 LSAs are replaced by the Area Border Router(ABR) with a default router. Totally stubby areas protect internal routers by minimizing the routing table and summarizing everything outside the area with a default route." (CCNP BSCI Official Exam Certification Guide, Fourth Edition) In conclusion, we have to configure area 1 as a totally stubby area. We do that by configuring Portland as stub and configuring Amani (ABR router) as a stub + "no-summary"suffix. + Configure Portland router as a stub: Portland#configure terminal Portland(config)#router ospf 1 Allow network 192.168.4.4/30 to join Area 1, notice that you have to convert subnet mask into wildcard mask: Portland(config-router)#network 192.168.4.4 0.0.0.3 area 1 Configure Portland as a stub: Portland(config-router)#area 1 stub Portland(config-router)#end Portland#copy running-config startup-config + Configure Amani router as a "totally stub": Amani#configure terminal Amani(config)#router ospf 1 Amani(config-router)#network 192.168.4.4 0.0.0.3 area 1 Make area 1 become a totally stubby area, notice that we can only use this command on ABR router: Amani(config-router)#area 1 stub no-summary Amani(config-router)#end Amani#copy running-config startup-config Ensurepass offers the Latest 2013 642-902 Exam PDF to pass the exams.