Ensurepass

QUESTION 41

DRAG DROP

QUESTION 42

Which type of EIGRP route entry describes a feasible successor?

 A. a backup route, stored in the routing table B. a primary route, stored in the routing table C. a backup route, stored in the topology table D. a primary route, stored in the topology table

Explanation:

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f07.shtml

Feasible Successors

A destination entry is moved from the topology table to the routing table when there is a feasible successor. All minimum cost paths to the destination form a set. From this set, the neighbors that have an advertised metric less than the current routing table metric are considered feasible successors.

Feasible successors are viewed by a router as neighbors that are downstream with respect to the destination.

These neighbors and the associated metrics are placed in the forwarding table.

When a neighbor changes the metric it has been advertising or a topology change occurs in the network, the set of feasible successors may have to be re-evaluated. However, this is not categorized as a route recomputation.

Feasible successor is a route whose Advertised Distance (AD) is less than the Feasible Distance (FD) of the current best path. A feasible successor is a backup route, which is not stored in the routing table but, stored in the topology table.

QUESTION 43

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.

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.

QUESTION 44

What are two enhancements that OSPFv3 supports over OSPFv2? (Choose two.)

 A. It requires the use of ARP. B. It can support multiple IPv6 subnets on a single link. C. It supports up to 2 instances of OSPFv3 over a common link. D. It routes over links rather than over networks.

Explanation:

Here is a list of the differences between OSPFv2 and OSPFv3:

They use different address families (OSPFv2 is for IPv4-only, OSPFv3 can be used for IPv6-only or both protocols

OSPFv3 introduces new LSA types

OSPFv3 has different packet format

OSPFv3 uses different flooding scope bits (U/S2/S1)

OSPFv3 runs per-link rather than per-subnet

OSPFv3 supports multiple instances on a single link, Interfaces can have multiple IPv6 addresses

OSPFv3 uses multicast addresses FF02::5 (all OSPF routers), FF02::6 (all OSPF DRs)

OSPFv3 Neighbor Authentication done with IPsec (AH)

OSPFv2 Router ID (RID) must be manually configured, still a 32-bit number

Reference: http://www.networkworld.com/article/2225270/cisco-subnet/ospfv3-for-ipv4-and-ipv6.html

QUESTION 45

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

Explanation:

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.

QUESTION 46

Which command is used to display the collection of OSPF link states?

 A. show ip ospf link-state B. show ip ospf lsa database C. show ip ospf neighbors D. show ip ospf database

Explanation:

http://www.cisco.com/en/US/docs/ios/iproute_ospf/command/reference/iro_osp3.html#wp101217

Examples

The following is sample output from the show ip ospf database command when no arguments or keywords are used:

Router# show ip ospf database

OSPF Router with id(192.168.239.66) (Process ID 300)

QUESTION 47

What can be done to secure the virtual terminal interfaces on a router? (Choose two.)

 A. Administratively shut down the interface. B. Physically secure the interface. C. Create an access list and apply it to the virtual terminal interfaces with the access-group command. D. Configure a virtual terminal password and login process. E. Enter an access list and apply it to the virtual terminal interfaces using the access-class command.

Explanation:

It is a waste to administratively shut down the interface. Moreover, someone can still access the virtual terminal interfaces via other interfaces -> A is not correct.

We can not physically secure a virtual interface because it is “virtual” -> B is not correct. To apply an access list to a virtual terminal interface we must use the “access-class” command. The “access-group” command is only used to apply an access list to a physical interface -> C is not correct; E is correct.

The most simple way to secure the virtual terminal interface is to configure a username & password to prevent unauthorized login -> D is correct.

QUESTION 48

Refer to the exhibit. Which three EIGRP routes will be present in the router R4’s routing table? (Choose three.)

 A. 172.16.1.0/24 B. 10.1.10.0/30 C. 10.0.0.0/8 D. 10.1.11.0/30 E. 172.16.0.0/16 F. 192.168.1.0/24

Explanation:

EIGRP performs an auto-summarization each time it crosses a border between two different major networks, so when R2 advertises the routes to R4 it will advertise only the summarized routes of 10.0.0.0/8 and 172.16.0.0/16, along with the 192.168.1.0/24 route coming from R3.

QUESTION 49

Refer to the exhibit. Which two st
atements are true about the loopback address that is configured on RouterB? (Choose two.)

 A. It ensures that data will be forwarded by RouterB. B. It provides stability for the OSPF process on RouterB. C. It specifies that the router ID for RouterB should be 10.0.0.1. D. It decreases the metric for routes that are advertised from RouterB. E. It indicates that RouterB should be elected the DR for the LAN.

Explanation:

A loopback interface never comes down even if the link is broken so it provides stability for the OSPF process (for example we use that loopback interface as the router-id) – B is correct.

The router-ID is chosen in the order below:

The highest IP address assigned to a loopback (logical) interface. If a loopback interface is not defined, the highest IP address of all active router’s physical interfaces will be chosen.

The loopback interface will be chosen as the router ID of RouterB – C is correct.

QUESTION 50

Refer to the exhibit. The Lakeside Company has the internetwork in the exhibit. The administrator would like to reduce the size of the routing table on the Central router. Which partial routing table entry in the Central router represents a route summary that represents the LANs in Phoenix but no additional subnets?

 A. 10.0.0.0/22 is subnetted, 1 subnets D 10.0.0.0 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1 B. 10.0.0.0/28 is subnetted, 1 subnets D 10.2.0.0 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1 C. 10.0.0.0/30 is subnetted, 1 subnets D 10.2.2.0 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1 D. 10.0.0.0/22 is subnetted, 1 subnets D 10.4.0.0 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1 E. 10.0.0.0/28 is subnetted, 1 subnets D 10.4.4.0 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1 F. 10.0.0.0/30 is subnetted, 1 subnets D 10.4.4.4 [90/20514560] via 10.2.0.2, 6w0d, Serial0/1