Q41. - (Topic 2) 

Which commands are required to properly configure a router to run OSPF and to add network 192.168.16.0/24 to OSPF area 0? (Choose two.) 

A. Router(config)# router ospf 0 

B. Router(config)# router ospf 1 

C. Router(config)# router ospf area 0 

D. Router(config-router)# network 192.168.16.0 0.0.0.255 0 

E. Router(config-router)# network 192.168.16.0 0.0.0.255 area 0 

F. Router(config-router)# network 192.168.16.0 255.255.255.0 area 0 

Answer: B,E 

Explanation: 

In the router ospf Command, the ranges from 1 to 65535 so o is an invalid number - B is correct but A is not correct. To configure OSPF, we need a wildcard in the “network” statement, not a subnet mask. We also need to assign an area to this process - E is correct. 


Q42. - (Topic 2) 

Refer to the exhibit. 

When running EIGRP, what is required for RouterA to exchange routing updates with RouterC? 

A. AS numbers must be changed to match on all the routers 

B. Loopback interfaces must be configured so a DR is elected 

C. The no auto-summary command is needed on Router A and Router C 

D. Router B needs to have two network statements, one for each connected network 

Answer: A Explanation: 

Here we required same autonomous system between router A,B,C.Routing updated always exchange between in same EIGRP EIGRP autonomous system.you can configure more than one EIGRP autonomous system on the same router. This is typically done at a redistribution point where two EIGRP autonomous systems are interconnected. Individual router interfaces should only be included within a single EIGRP autonomous system. Cisco does not recommend running multiple EIGRP autonomous systems on the same set of interfaces on the router. If multiple EIGRP autonomous systems are used with multiple points of mutual redistribution, it can cause discrepancies in the EIGRP topology table if correct filtering is not performed at the redistribution points. If possible, Cisco recommends you configure only one EIGRP autonomous system in any single autonomous system. http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f07.shtml 


Q43. - (Topic 2) 

What information does a router running a link-state protocol use to build and maintain its topological database? (Choose two.) 

A. hello packets 

B. SAP messages sent by other routers 

C. LSAs from other routers 

D. beacons received on point-to-point links 

E. routing tables received from other link-state routers 

F. TTL packets from designated routers 

Answer: A,C 

Explanation: 

Link State Routing Protocols http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=4 

Link state protocols, sometimes called shortest path first or distributed database protocols, are built around a well-known algorithm from graph theory, E. W. Dijkstra'a shortest path algorithm. Examples of link state routing protocols are: Open Shortest Path First (OSPF) for IP The ISO's Intermediate System to Intermediate System (IS-IS) for CLNS and IP DEC's DNA Phase V Novell's NetWare Link Services Protocol (NLSP) Although link state protocols are rightly considered more complex than distance vector protocols, the basic functionality is not complex at all: 

1. Each router establishes a relationship—an adjacency—with each of its neighbors. 

2. Each router sends link state advertisements (LSAs), some 

3. Each router stores a copy of all the LSAs it has seen in a database. If all works well, the databases in all routers should be identical. 

4. The completed topological database, also called the link state database, describes a graph of the internetwork. Using the Dijkstra algorithm, each router calculates the shortest path to each network and enters this information into the route table. 


Q44. - (Topic 2) 

Refer to the exhibit. 

Assume that all router interfaces are operational and correctly configured. In addition, assume that OSPF has been correctly configured on router R2. How will the default route configured on R1 affect the operation of R2? 

A. Any packet destined for a network that is not directly connected to router R1 will be dropped. 

B. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately. 

C. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1. 

D. The networks directly connected to router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.128, and 172.16.100.64 subnetworks. 

E. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur. 

Answer:

Explanation: 

First, notice that the more-specific routes will always be favored over less-specific routes regardless of the administrative distance set for a protocol. In this case, because we use OSPF for three networks (172.16.100.0 0.0.0.3, 172.16.100.64 0.0.0.63, 172.16.100.128 0.0.0.31) so the packets destined for these networks will not be affected by the default route. The default route configured on R1 "ip route 0.0.0.0 0.0.0.0 serial0/0 will send any packet whose destination network is not referenced in the routing table of router R1 to R2, it doesn't drop anything so answers A, B and C are not correct. D is not correct too because these routes are declared in R1 and the question says that "OSPF has been correctly configured on router R2, so network directly connected to router R2 can communicate with those three subnetworks. As said above, the default route configured on R1 will send any packet destined for a network that is not referenced in its routing table to 

R2; R2 in turn sends it to R1 because it is the only way and a routing loop will occur. 


Q45. - (Topic 2) 

Refer to the exhibit. 

Based on the exhibited routing table, how will packets from a host within the 192.168.10.192/26 LAN be forwarded to 192.168.10.1? 

A. The router will forward packets from R3 to R2 to R1. 

B. The router will forward packets from R3 to R1 to R2. 

C. The router will forward packets from R3 to R2 to R1 AND from R3 to R1. 

D. The router will forward packets from R3 to R1. 

Answer:

Explanation: 

From the routing table we learn that network 192.168.10.0/30 is learned via 2 equal- cost paths (192.168.10.9 &192.168.10.5) - traffic to this network will be load-balanced. 


Q46. - (Topic 3) 

Which command is used to enable CHAP authentication, with PAP as the fallback method, on a serial interface? 

A. Router(config-if)# ppp authentication chap fallback ppp 

B. Router(config-if)# ppp authentication chap pap 

C. Router(config-if)# authentication ppp chap fallback ppp 

D. Router(config-if)# authentication ppp chap pap 

Answer:

Explanation: 

The command “ppp authentication chap pap” command indicates the CHAP authentication is used first. If it fails or is rejected by other side then uses PAP instead. If you want to use PAP first (then CHAP) you can use the “ppp authentication pap chap” command 

Reference: http://www.cisco.com/en/US/docs/ios/12_2/security/configuration/guide/scfathen.html 


Q47. - (Topic 2) 

A router is running three routing processes: RIP, OSPF, and EIGRP, each configured with default characteristics. Each process learns a route to the same remote network. 

If there are no static routes to the destination and none of the routes were redistributed, which route will be placed in the IP routing table? 

A. the route learned through EIGRP 

B. the route learned through OSPF 

C. the route learned through RIP 

D. the route with the lowest metric 

E. all three routes with the router load balancing 

Answer:

Reference: 

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094195.shtml 

Administrative distance is the feature that routers use in order to select the best path. 

Administrative distance defines the reliability of a routing protocol. Each routing protocol is prioritized in order of most to least reliable (believable) with the help of an administrative distance value. Lowest Administrative distance will be chosen first. 


Q48. - (Topic 3) 

Refer to the exhibit. 

A network associate has configured OSPF with the command: City(config-router)# network 192.168.12.64 0.0.0.63 area 0 After completing the configuration, the associate discovers that not all the interfaces are participating in OSPF. Which three of the interfaces shown in the exhibit will participate in OSPF according to this configuration statement? (Choose three.) 

A. FastEthernet0 /0 

B. FastEthernet0 /1 

C. Serial0/0 

D. Serial0/1.102 

E. Serial0/1.103 

F. Serial0/1.104 

Answer: B,C,D 

Explanation: 

The “network 192.168.12.64 0.0.0.63 equals to network 192.168.12.64/26. This network has:Increment: 64 (/26= 1111 1111.1111 1111.1111 1111.1100 0000)Network address: 

192.168.12.64 Broadcast address: 192.168.12.127Therefore all interface in the range of this network will join OSPF - B C D are correct. 


Q49. - (Topic 2) 

What OSPF command, when configured, will include all interfaces into area 0? 

A. network 0.0.0.0 255.255.255.255 area 0 

B. network 0.0.0.0 0.0.0.0 area 0 

C. network 255.255.255.255 0.0.0.0 area 0 

D. network all-interfaces area 0 

Answer:

Explanation: 

Example 3-1 displays OSPF with a process ID of 1 and places all interfaces configured with 

an IP address in area 0. The network command.network 0.0.0.0 255.255.255.255 area 0.dictates that you do not care (255.255.255.255) what the IP address is, but if an IP 

address is enabled on any interface, place it in area 0. 

Example 3-1.Configuring OSPF in a Single Area 

router ospf 1 network 0.0.0.0 255.255.255.255 area 0 Reference: http://www.ciscopress.com/articles/article.asp?p=26919&seqNum=3 


Q50. - (Topic 1) 

Refer to the exhibit 

Which switch provides the spanning-tree designated port role for the network segment that services the printers? 

A. Switch1 

B. Switch2 

C. Switch3 

D. Switch4 

Answer:

Explanation: 

First, the question asks what switch services the printers, so it can be Switch 3 or Switch 4 

which is connected directly to the Printers. 

Designated port is a port that is in the forwarding state. All ports of the root bridge are 

designated ports. 

Switch 3 and Switch 4 has same priority so it will see on lowest MAC address and here 

switch 3 has lowest MAC address. So switch 3 segment will play a Designated port role. 

By comparing the MAC address of Switch 3 and Switch 4 we found that the MAC of Switch 

3 is smaller. Therefore the interface connected to the Printers of Switch 3 will become 

designated interface and the interface of Switch 4 will be blocked.