chapter 6

Which of the following best describes how a router operates to transmit messages to different LAN segments?

The router reads the LAN segment address contained in the message and consults the appropriate routing table for the protocol, then forwards the message to the appropriate LAN segment.

Which of the following statements about routers are true? (Select two.)

They examine the destination device address contained in packets to make routing decisions.

They use logical network and device addresses to route data between networks.

How does a router use frames to route data through a network?

The router checks the MAC address in the frame, replaces the MAC address of the source with its own MAC address, and sends it to the proper host.

Which processes does Cisco express forwarding (CEF) use to optimize packet processing through a router? (Select two.)

Organizes routing data in the forwarding information base (FIB).

Maintains adjacency tables.

Which internal routing logic organizes routing data using a tree structure, which allows very fast searches and requires less time to route packets?

Cisco express forwarding

You are designing a routing solution for your organization. You want to improve routing efficiency by ensuring that routers save frequently used data link headers to encapsulate packets.

Which types of routing logic could you implement? (Select two.)

Cisco express forwarding

Fast switching

Which Cisco express forwarding mechanism maintains Layer 2 information linked to a particular entry in the routing table, reducing the need to send ARP requests before forwarding packets?

Adjacency tables

Match each default administrative distance with the correct route type. (Each item may be used once, more than once, or not at all.)

EIGRP internal routes - 90

EIGRP external routes - 170

OSPF - 110

RIP - 120

Static routes - 1

Which of the following best describes a hop count?

The number of routers needed to get to the destination network.

The administrative distance determines the trustworthiness of the route source. Assuming that two separate routes are available to the same location, the router will use the following criteria for choosing between these routes. Put the criteria in order.

1 - If a static route is available, it is selected.

\
2 - If a router has learned of two routes to a single network through different routing protocols, it chooses the route with the lowest administrative distance.

\
3 - If a router has learned of two routes through the same protocol, the router will choose the route that has the best cost as defined by the routing metric.

Match each routing method on the left with its associated characteristics on the right. Each routing method may be used once, more than once, or not at all.

Most appropriate on small networks.

Static routing

\
Propagates changes in the network topology.

Dynamic routing

\
Provides complete control over routes.

Static routing

\
Most appropriate on networks that don't change frequently

Static routing

\
Keeps routing tables on each router up to date.

Dynamic routing

If you have one router on your network and the IP address doesn't match one of the devices on your network, where would the default static route direct packets?

To your Internet Service Provider

Which of the following is a disadvantage of static routing?

Require more configuration time

Match each route types with its description.

Used to minimize the number of routing table entries.

Summary static route

\
Works best when only one path exists to a part of the network.

Default static route

\
Used when connecting to a remote network.

Standard static route

\
Is a backup route.

Floating static route

You have issued the following command on your router:

Router(config)#ip route 202.22.12.0 255.255.255.0 192.168.1.1

Which of the following are configured by the parameters in this command? (Select two.)

A route to network 202.22.12.0 is added.

The next hop router address is 192.168.1.1.

You are the administrator of the network shown. You want to configure the stub network located in Tampa to forward packets to Chicago, but you do not want the overhead associated with a routing protocol. Which of the following will accomplish your goal?

Tampa(config)#**ip route 0.0.0.0 0.0.0.0 182.1.48.3** \n Chicago(config)#**ip route 182.1.48.0 255.255.240.0 182.1.48.4** \n Chicago(config)#**ip route 192.168.112.128 255.255.255.248 182.1.48.4**

You need to configure a static route on your Cisco router. The destination network is 192.65.178.0 with a subnet mask of 255.255.255.0. The default gateway is 192.65.179.1, and the IP address of the destination host for the message is 192.65.178.15.

Which of the following commands configures this route?

**ip route 192.65.178.0 255.255.255.0 192.65.179.1**

You have a small network as shown. You want to configure a route so that packets sent to any non-directly connected network get sent to RouterB.

Which command would you use?

**ip route 0.0.0.0 0.0.0.0 192.168.4.14**

You have a small network as shown. You have configured RIP on both RouterA and RouterB. The **show ip route** command on RouterA shows the following information:

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP \n D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area \n N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 \n E1 - OSPF external type 1, E2 - OSPF external type 2 \n i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 \n ia - IS-IS inter area, \* - candidate default, U - per-user static route \n o - ODR, P - periodic downloaded static route \n

Gateway of last resort is not set \n

R 10.0.0.0/8 \[120/1\] via 192.168.4.14, 00:00:02, Serial0/1/0 \n C 192.168.1.0/24 is directly connected, FastEthernet0/0 \n   192.168.4.0/30 is subnetted, 1 subnets \n C 192.168.4.12 is directly connected, Serial0/1/0 

You want to configure a default route so that all packets for unknown networks are sent to RouterB. Which command should you use?

**ip default-network 10.0.0.0**

You have a small network as shown. You have configured RIP on both RouterA and RouterB. The **show ip route** command on RouterA shows the following information:

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP \n D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area \n N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 \n E1 - OSPF external type 1, E2 - OSPF external type 2 \n i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 \n ia - IS-IS inter area, \* - candidate default, U - per-user static route \n o - ODR, P - periodic downloaded static route \n

Gateway of last resort is not set \n

R 10.0.0.0/8 \[120/1\] via 192.168.4.2, 00:00:02, FastEthernet0/1 \n C 192.168.1.0/24 is directly connected, FastEthernet0/0 \n C\* 192.168.4.0/24 is directly connected, FastEthernet0/1 \n C 192.168.2.0/24 is directly connected, FastEthernet0/2

RouterA receives a packet addressed to 172.16.0.1. What will RouterA do with the packet?

Drop the packet.

Which of the following are the main components of Dynamic Routing Protocols? (Select three.)

Algorithm

Routing protocol messages

Data structures

Which of the following is an EGP that an ISP uses to send packets across the internet from one internal network to another?

Border Gateway Protocol (BGP)

Which protocol was created in the 1980s, was improved over the years, and is still used for small networks?

RIP

Which of the following are true about the distance vector method of sharing routing table information? (Select two.)

Routers send routing information only to their neighbor routers.

The entire routing table is sent to neighbor routers.

Which of the following methods of preventing the count-to-infinity problem with distance vector routers will send a hop count of 16 back up the path from which the information was obtained?

Split horizon with poison reverse

Which feature implemented with a Distance Vector Routing Protocol reduces the convergence time?

Triggered updates

Which of the following are components of a Link-State Routing Protocol? (Select three.)

Routing table of paths and ports

SPF tree

Hello packets

Which of the following are problems typically associated with the link-state routing method? (Select two.)

Increased use of router hardware resources.

High traffic to build routing tables.

How are Distance Vector Routing Protocols similar to Link-State Routing Protocols? (Select two.)

The Distance Vector Routing Protocol RIP and the Link-State Routing Protocol OSPF are both interior gateway protocols.

\
The trustworthiness of both types of routing protocols is rated by an administrative distance.

Which protocol can have a higher Memory and CPU requirement than the others?

OSPF

Paul executed the **show interfaces** command and reviewed the output. Which output indicates a Layer 2 problem with the Serial0/1/1 interface?

Serial0/1/1 is up, line protocol is down.

Kathy executed the **show interfaces** command on a router and reviewed the output. Which output indicates a Layer 1 problem with the Serial0/1/1 interface?

Serial0/1/1 is down, line protocol is down.

When attempting to make a Telnet connection to a remote router, the connection fails. You check the interface status on your local router and find the following:

Serial0/1/0 is up, line protocol is up \n    Hardware is GT96K Serial \n    Internet address is 192.168.2.1/24 \n    MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, \n    reliability 255/255, txload 1/255, rxload 1/255 \n    Encapsulation HDLC, loopback not set \n    Keepalive set (10 sec)... (additional output omitted)

You ping the remote router, but that fails as well. At which layer of the OSI model does this problem originate?

Layer 3

IP traffic destined for a device configured with the address 10.10.34.4/24 is congesting the network. The network administrator issues a **traceroute** command from the local router and receives the following output:

Router#traceroute 10.10.34.4

\n Type escape sequence to abort. \n Tracing the route to 10.10.34.4

\n   1 192.168.12.2 20 msec 20 msec 20 msec \n   2 192.168.12.1 8 msec 12 msec 8 msec \n   3 192.168.12.2 8 msec 8 msec 12 msec \n   4 192.168.12.1 12 msec 8 msec 8 msec \n   5 192.168.12.2 8 msec 8 msec 12 msec \n   6 192.168.12.1 8 msec 12 msec 8 msec \n

! -- remaining output omitted -- 

What is the cause of the problem?

A loop exists between two of the routers.

RouterA, RouterB, and RouterC have been configured with IP addresses set as shown. All networks are using the default subnet mask.

Users in network 10.1.1.0 claim they cannot access resources in network 192.168.2.0. From network 10.1.1.0, you can successfully ping interface 172.16.32.2, but you cannot ping 172.16.32.1. Another administrator on 192.168.2.0 claims she can ping 192.168.2.1, but not 172.16.32.1.

What is most likely the problem?

The S0/1/1 interface on Router C is administratively down.

You are working at the console of a new router. You want to check the configuration of a neighboring router called Sales5. You type **telnet Sales5** at the router prompt and receive the following message:

Translating "Sales5"...domain server (255.255.255.255) \n % Unknown command or computer name, or unable to find computer address

What should you do?

Configure an address of a DNS server for the router to contact.

Network users are complaining that they can connect to resources within the company, but cannot use the internet. The network administrator begins troubleshooting the problem by entering privileged EXEC mode on the company router and typing the **show ip route** command.

What is the most probable cause of the problem?

An incorrect next-hop route is statically configured on the local router.

Last night, an administrator connected a new router to his network and enabled the RIP routing protocol. This morning, when the administrator returned, he discovered the router wasn't forwarding packets to networks connected to the Serial1 interface. He examines the routing table using the command **show ip route**. 

What could be the cause of the problem?

The Serial1 interface is administratively shut down.

Router_1 is connected to three networks, 192.168.0.0, 172.16.16.0, and 172.16.32.0. An administrator enables the RIP routing protocol on Router_1. The router isn't forwarding packets to network 172.16.16.0. The administrator examines the configuration on Router_1 using the **sh run** command.

What should the administrator do to correct the problem?

Enable the Serial0 interface.

The administrator of a corporate network is receiving complaints from internal users that they cannot access the internet. The administrator displays the routing table of the local router using the **show ip route** command.

What should the administrator do on the local router to provide internal users access to the internet?

Configure a default route using **ip route 0.0.0.0 0.0.0.0 131.108.2.2**.

You have a small network as shown.

The user on workstation A reports that she cannot communicate with remote workstation D. You begin to troubleshoot the problem by sending a ping from workstation A to the remote workstation D, but it does not reply. Next, you try sending a ping from workstation A to the remote workstation C, and it replies successfully.

Which of the following can you assume based on these results?

The problem is with the configuration or connectivity of remote workstation D.

You have a small network as shown.

The user on workstation A reports that he cannot communicate with remote workstation E. You begin to troubleshoot the problem by sending a ping from workstation A to remote workstation E, but you cannot reach this host. Next, you try sending pings from workstation A to the remote workstations C and D, and you cannot reach either of them. You also try pinging the IP address assigned to interface 1 on the Default Gateway router, which is also unsuccessful. Finally, you ping workstation B, and this time, you get a successful reply.

Which of the following can you assume based on these results?

There is a problem with the default gateway router.

You have a workstation connected to a small network with one subnet. The subnet is connected to the internet through a local ISP.

You are having trouble connecting to one of your favorite websites. You issue a tracert command and see the output shown below:

C:\\tracert 166.77.11.1
Tracing route to 166.77.11.1 over a maximum of 30 hops

1 \* \* \* Request timed out.
2 \* \* \* Request timed out.
3 \* \* \* Request timed out.
4 \* \* \* Request timed out.
\--additional output omitted

Which of the following is the most likely cause of the problem? (Select two.)

The local workstation is configured with an incorrect default gateway address.

Your local router is down.

Which of the following utilities gives you the most information about the operational status of a router?

**telnet**

You have a workstation connected to a small network with one subnet. The subnet is connected to the internet through a local ISP.

You are having trouble connecting to one of your favorite websites. You issue a **tracert** command and see the output shown below:

Which of the following is the most likely cause of the problem? (Select two.)

The destination network can be reached, but the host does not respond.

A router in the path does not have a route to the destination network.

You have a Windows workstation connected to a small network. Match each function on the left with its associated utility on the right.

ipconfig - View the configured IP address, subnet mask, and default gateway

\
ping - Test Layer 3 functionality

\
tracert - Test Layer 3 functionality

\
ssh - Test Layer 7 functionality

\
telnet - Test Layer 7 functionality

\
arp - Clear the MAC address table

Which of the following commands lists a workstation's ARP cache?

**arp -a**

You have just connected a Windows workstation to the network. The workstation can communicate with all devices on the same subnet, but can't communicate with other devices on other subnets. You use the **ipconfig** command on the workstation and see the following:

C:\\ipconfig \n Windows IP Configuration \n Ethernet adapter Local Area Connection: \n     IP Address . . . . . . . . . . : 192.168.1.100 \n     Subnet Mask. . . . . . . . . . : 255.255.255.0 \n     Default Gateway. . . . . . . . : 192.168.1.1

No other devices seem to have an issue. What is the most probable cause of the problem?

The wrong default gateway address has been configured.

A network administrator is located in a subnet connected to Switch P1 as shown. The administrator is unable to ping Switch A1 connected to the Atlanta router. What is the cause of the problem?

An incorrect default-gateway address is configured on Switch A1.

You have a small network as shown in the Exhibit. You are unable to ping Wrk2 from Wrk1. What should you do to fix the problem?

Change the IP address assigned to Wrk2.