CCNA 2 - Module 2 Exam Answers

1. Hosts on two separate subnets cannot communicate. The network administrator suspects a missing route in one of the routing tables. Which three commands can be used to help troubleshoot Layer 3 connectivity issues? (Choose three.)

* ping
show arp
* traceroute
* show ip route
show interface
show cdp neighbor detail

2. What address can be used to summarize networks 172.16.1.0/24, 172.16.2.0/24, 172.16.3.0/24, and 172.16.4.0/24?

* 172.16.0.0/21
172.16.1.0/22
172.16.0.0 255.255.255.248
172.16.0.0 255.255.252.0

3. The routers in the diagram use the subnet assignments shown. What is the most efficient route summary that can be configured on Router3 to advertise the internal networks to the cloud?

192.1.1.0/26 and 192.1.1.64/27
192.1.1.128/25
192.1.1.0/23 and 192.1.1.64/23
192.1.1.0/24
* 192.1.1.0/25
192.1.1.0/24 and 192.1.1.64/24

4. Refer to the exhibit. What is the significance of the /8 in the route to the 10.0.0.0 network?

It indicates that there are 8 hops between this router and the 10.0.0.0 network.
It represents the time, in milliseconds, it takes for a ping to reply when sent to the 10.0.0.0 network.
It indicates that there are 8 subnets in the destination network to which the router can forward packets.
* It indicates the number of consecutive bits, from the left, in the destination IP address of a packet that must match 10.0.0.0 to use that route.

5. Refer to the exhibit. How will packets destined to the 172.16.0.0 network be forwarded?

* Router1 will perform recursive lookup and packet will exit S0/0.
Router1 will perform recursive lookup and packet will exit S0/1.
There is no matching interface associated with network 172.16.0.0 so packets will be dropped.
There is no matching interface associated with network 172.16.0.0 so packets will take gateway of last resort and exit out S0/2.

6. A network administrator enters the following command into Router1: ip route 192.168.0.0 255.255.255.0 S0/1/0. Router1 then receives a packet that is destined for 192.168.0.22/24. After finding the recently configured static route in the routing table, what does Router1 do next to process the packet?

drops the packet because the destination host is not listed in the routing table
looks up the MAC address of the S0/1/0 interface to determine the destination MAC address of the new frame
performs a recursive lookup for the IP address of the S0/1/0 interface before forwarding the packet
* encapsulates the packet into a frame for the WAN link and forwards the packet out the S0/1/0 interface

7. Refer to the exhibit. Given the output in the exhibit, how would a clock rate be determined for this link?

The rate would be negotiated by both routers.
A rate would not be selected due to the DCE/DTE connection mismatch.
The rate configured on the DTE determines the clock rate.
* The rate configured on the DCE determines the clock rate.

8. Refer to the exhibit. Which set of commands will configure static routes that will allow the WinterPark and the Altamonte routers to deliver packets from each LAN and direct all other traffic to the Internet?

* WinterPark(config)# ip route 0.0.0.0 0.0.0.0 192.168.146.1
Altamonte(config)# ip route 10.0.234.0 255.255.255.0 192.168.146.2
Altamonte(config)# ip route 0.0.0.0 0.0.0.0 s0/1
WinterPark(config)# ip route 0.0.0.0 0.0.0.0 192.168.146.1
Altamonte(config)# ip route 10.0.234.0 255.255.255.0 192.168.146.2
Altamonte(config)# ip route 198.18.222.0 255.255.255.255 s0/1
WinterPark(config)# ip route 172.191.67.0 255.255.255.0 192.168.146.1
WinterPark(config)# ip route 0.0.0.0 0.0.0.0 192.168.146.1
Altamonte(config)# ip route 10.0.234.0 255.255.255.0 192.168.146.2
WinterPark(config)# ip route 172.191.67.0 255.255.255.0 192.168.146.1
Altamonte(config)# ip route 10.0.234.0 255.255.255.0 192.168.146.2
Altamonte(config)# ip route 0.0.0.0 0.0.0.0 s0/0


9. A static route that points to the next hop IP will have what administrative distance and metric in the routing table?

administrative distance of 0 and metric of 0
administrative distance of 0 and metric of 1
* administrative distance of 1 and metric of 0
administrative distance of 1 and metric of 1

10. Refer to the exhibit. A company network engineer is assigned to establish connectivity between the two Ethernet networks so that hosts on the 10.1.1.0/24 subnet can contact hosts on the 10.1.2.0/24 subnet. The engineer has been told to use only static routing for these company routers. Which set of commands will establish connectivity between the two Ethernet networks?

R1(config)# ip route 10.1.2.0 255.255.255.0 192.168.0.1
R2(config)# ip route 10.1.1.0 255.255.255.0 192.168.0.2
R1(config)# ip route 10.1.2.0 255.255.255.0 192.168.0.2
R2(config)# ip route 10.1.1.0 255.255.255.0 192.168.0.1
* R1(config)# ip route 10.1.1.0 255.255.255.0 192.168.0.2
R2(config)# ip route 10.1.2.0 255.255.255.0 192.168.0.1
R1(config)# ip route 10.1.1.0 255.255.255.0 192.168.0.1
R2(config)# ip route 10.1.2.0 255.255.255.0 192.168.0.2
R1(config)# ip route 0.0.0.0 0.0.0.0 10.1.2.1
R2(config)# ip route 0.0.0.0 0.0.0.0 10.1.1.1

11. Which of the following are displayed by the Router# show cdp neighbors command? (Choose three.)

load
* platform
reliability
* holdtime
* local interface

12. Refer to the exhibit. What two commands are required to provide connectivity between the 192.168.1.0 and 10.0.0.0 networks without requiring recursive lookup? (Choose two.)

* A(config)# ip route 10.0.0.0 255.0.0.0 s 0/1/0
A(config)# ip route 10.0.0.0 255.0.0.0 172.16.40.2
A (config)# ip route 10.0.0.0 255.0.0.0 s 0/0/0
* B(config)# ip route 192.168.1.0 255.255.255.0 s 0/0/0
B (config)# ip route 192.168.1.0 255.255.255.0 172.16.40.1
B(config)# ip route 192.168.1.0 255.255.255.0 s 0/1/0

13.Refer to the exhibit. What two commands will change the next-hop address for the 10.0.0.0/8 network from 172.16.40.2 to 192.168.1.2? (Choose two.)

A(config)# no network 10.0.0.0 255.0.0.0 172.16.40.2
A(config)# no ip address 10.0.0.1 255.0.0.0 172.16.40.2
* A(config)# no ip route 10.0.0.0 255.0.0.0 172.16.40.2
A(config)# ip route 10.0.0.0 255.0.0.0 s0/0/0
* A(config)# ip route 10.0.0.0 255.0.0.0 192.168.1.2

14. What happens to a static route entry in a routing table when the outgoing interface is not available?

* The route is removed from the table.
The router polls neighbors for a replacement route.
The route remains in the table because it was defined as static.
The router redirects the static route to compensate for the loss of the next hop device.

15. A router has one static route to each destination network. Which two scenarios would require an administrator to alter the static routes that are configured on that router? (Choose two.)

* The destination network no longer exists.
The destination network is moved to a different interface on the same router.
The path between the source and destination is upgraded with a higher bandwidth link.
* A topology change occurs where the existing next-hop address or exit interface is not accessible.
The remote destination network interface has to be down for 15 minutes of maintenance.

16. Why is it advisable to enter a next-hop IP address when creating a static route whose exit interface is an Ethernet network?

Adding the next-hop address eliminates the need for the router to do any lookups in the routing table before forwarding a packet.
* In a multi-access network, the router cannot determine the next-hop MAC address for the Ethernet frame without a next-hop address.
Using a next-hop address in a static route provides a route with a lower metric.
In multi-access networks, using a next-hop address in a static route makes that route a candidate default route.

17. The output of the Router# show interfaces serial 0/1 command displays the following:

Serial0/1 is up, line protocol is down.

What is the most likely cause for the line protocol being down?

Serial0/1 is shutdown.
There is no cable connecting the routers.
The remote router is using serial 0/0.
* No clock rate has been set.

18.Refer to the exhibit. Which static route should be configured on Router1 so that host A will be able to reach host B on the 172.16.0.0 network?

ip route 192.168.0.0 172.16.0.0 255.255.0.0
ip route 172.16.0.0 255.255.0.0 192.168.0.1
ip route 172.16.0.0 255.255.0.0 S0/0/1
* ip route 172.16.0.0 255.255.0.0 S0/0/0

19 .Which piece of information is available from examining the output of the command show ip interface brief?

Interface speed and duplex
Interface MTU
Errors
Interface MAC address
* Interface IP address

20.Which of the following is true regarding CDP and the graphic shown?

CDP running on Router D will gather information about routers A, B, C, and E.
* By default, Router A will receive CDP advertisements from routers B and C.
If routers D and E are running different routing protocols, they will not exchange CDP information.
Router E can use CDP to identify the IOS running on Router B.

21.Which two statements describe functions or characteristics of CDP? (Choose two.)

* It starts up automatically and allows the device to detect directly connected neighbor devices that use CDP.
It operates at the network layer and allows two systems to learn about each other.
It creates a topology map of the entire network.
* It allows systems to learn about each other even if different network layer protocols are configured.
It forwards advertisements about routes for faster convergence.

22. What two devices are responsible for converting the data from the WAN service provider into a form acceptable by the router? (Choose two).

the serial port of the router
* a modem
a switch
the ethernet port of the router
* a CSU/DSU device
a DTE device

CCNA 2 - Module 1 Exam Answers

1. If a router cannot find a valid configuration file during the startup sequence, what will occur?
The router will prompt the user for a response to enter setup mode.

2. Refer to the exhibit. The network administrator has configured the router with the interface IP addresses shown for the directly connected networks. Pings from the router to hosts on the connected networks or pings between router interfaces are not working. What is the most likely problem?
The interfaces must be enabled with the no shutdown command.

3. Refer to the exhibit. What can be concluded from the routing table output in the exhibit? (Choose two.)
The FastEthernet0/0 and Serial0/0/0 interfaces of this router were configured with an IP address and the no shutdown command.
An IP packet received by this router with a destination address of 198.18.9.1 will be forwarded out of the Serial0/0/0 interface.

4. Refer to the exhibit. The frame shown in the exhibit was received by the router. The router interfaces are operational. How will the router process this frame? (Choose two.)
The router will change the frame type to one supported by the WAN link before forwarding the frame.
The frame was received on the Fa0/0 interface of the router and will be switched to the S0/0/0 interface.

5. Passwords can be used to restrict access to all or parts of the Cisco IOS. Select the modes and interfaces that can be protected with passwords. (Choose three.)
VTY interface
console interface
privileged EXEC mode

6. Which two statements correctly describe the components of a router? (Choose two.)
ROM contains diagnostics executed on hardware modules.
Flash memory does not lose its contents during a reboot.

7. Refer to the exhibit. After host 2 is connected to the switch on the LAN, host 2 is unable to communicate with host 1. What is the cause of this problem?
The subnet mask of host 2 is incorrect.
Host 1 and host 2 are on different networks.
The switch needs an IP address that is not configured.
The router LAN interface and host 1 are on different networks.
The IP address of host 1 is on a different network than is the LAN interface of the router.

8. Which are functions of a router? (Choose three.)
packet switching
segmentation of broadcast domains
selection of best path based on logical addressing

9. Refer to the exhibit. All routers have a route in its routing table to each network that is shown in the exhibit. Default routes have not been issued on these routers. What can be concluded about how packets are forwarded in this network? (Choose two.)
If RouterA receives a packet that is destined for 192.168.3.146, it will be forwarded out interface S0/0/1.
If RouterB receives a packet that is destined for 10.5.27.15, it will be forwarded out interface S0/0/1.

10. The serial connection shown in the graphic needs to be configured. Which configuration commands must be made on the Sydney router to establish connectivity with the Melbourne site? (Choose three.)
Sydney(config-if)# ip address 201.100.53.2 255.255.255.0
Sydney(config-if)# no shutdown
Sydney(config-if)# clock rate 56000

11. Refer to the exhibit. What can be concluded from the output of the running-configuration of a router?
The commands that are displayed determine the current operation of the router.

12. Refer to the exhibit. Host A pings host B. When R4 accepts the ping into the Ethernet interface, what two pieces of header information are included? (Choose two.)
destination IP address: 192.168.10.134
destination MAC address: 9999.DADC.1234

13. What is the outcome of entering these commands?
R1(config)# line vty 0 4
R1(config-line)# password check123
R1(config-line)# login
sets the password to be used for connecting to this router via Telnet

14. Which of the following is the correct flow of routines for a router startup?
load bootstrap, load IOS, apply configuration

15. What three processes does a router execute when it receives a packet from one network that is destined for another network? (Choose three.)
decapsulates the Layer 3 packet by stripping off the Layer 2 frame header
uses the destination IP Address in the IP header to look up the next-hop address in the routing table
encapsulates the Layer 3 packet into the new Layer 2 frame and forwards it out the exit interface

16. The network administrator needs to connect two routers directly via their FastEthernet ports. What cable should the network administrator use?
cross-over
Which two statements describe characteristics of load balancing? (Choose two.)
Load balancing allows a router to forward packets over multiple paths to the same destination network.
Unequal cost load balancing is supported by EIGRP.

17. What information about the router and its startup process can be gathered from the output of the show version command? (Choose three.)
the last restart method
the configuration register settings
the location from where the IOS loaded

18. Which interfaces in the exhibit could be used for a leased line WAN connection? (Choose two.)
1
4

19. From what location can a router load the Cisco IOS during the boot process? (Choose two.)
TFTP server
Flash memory

20. A network administrator has just entered new configurations into Router1. Which command should be executed to save configuration changes to NVRAM?
Router1# copy running-config startup-config

21. What is the default sequence for loading the configuration file?
NVRAM, TFTP, CONSOLE


22. What header address information does a router change in the information it receives from an attached Ethernet interface before information is transmitted out another interface?
the Layer 2 source and destination address

CCNA 2 - An assignment on VLSM

Question:

Perform subnetting with the given address 180.180.0.0/16 as the address for the following topology:

Solution:

To perform subnetting with VLSM (concerning minimal wastage of host address) we will assign network address for various lans (in the given topology) sequentially, as follows:

a. Lan 1 : 8000 hosts

b. Lan 4 : 4000 hosts

c. Lan 5 : 4000 hosts

d. Lan 2 : 2000 hosts

e. Lan 3 : 1000 hosts

f. Lan 6: 500 hosts

g. Lan 7 : 254 hosts

h. Lan 8 : 50 hosts

a. Lan 1 : 8000 hosts:

We will use base address 180.180.0.0/16 to subnet for supporting 8000 hosts. We have to borrow 3 bits from the host portion for such subnetting. There will be 2³ =8 subnet each of which will have the subnet mask: 255.255.224.0.

So, Block size = (256-224) = 32 (network size).

The subnets are:

Subnet 0: 180.180.0.0/19

Subnet 1: 180.180.32.0/19

Subnet 2: 180.180.64.0/19

Subnet 3: 180.180.96.0/19

Subnet 4: 180.180.128.0/19

Subnet 5: 180.180.160.0/19

Subnet 6: 180.180.192.0/19

Subnet 7: 180.180.224.0/19

We will assign 180.180.0.0/19 (subnet 0) as the network address for lan 1.

1^st valid host address for lan 1: 180.180.0.1/19.

Last valid host address for lan 1: 180.180.31.254/19.

b. Lan 4: 4000 hosts:

We will use subnet 1: 180.180.32.0/19 as the base address to subnet for supporting 4000 hosts. We have to borrow 1 bit from the host portion for such subnetting. There will be 2¹=2 subnets, each of which will have the subnet mask: 255.255.240.0.

So, Block size = (256-240) =16 (network size).

Subnets are:

Subnet 10: 180.180.32.0/20

Subnet 11: 180.180.48.0/20

We will assign 180.180.32.0/20 (subnet 10) as the network address for lan 4.

1^st valid host address for lan 4: 180.180.32.1/20.

Last valid host address for lan 4: 180.180.47.254/20.

c. Lan 5 : 4000 hosts:

Subnet 11: 180.180.48.0/20 can support up to 2¹²-2 = 4096-2=4094 valid hosts.

So, we will assign 180.180.48.0/20 (subnet 11) as the network address for lan 5.

1^st valid host address for lan 5: 180.180.48.1/20.

Last valid host address for lan 5: 180.180.63.254/20.

d. Lan 2: 2000 hosts:

Now we will use subnet 2: 180.180.64.0/19 as the base address to subnet for supporting 2000 hosts. So, we have to borrow 2 bits from the host portion for such subnetting. There will be 2² = 4 subnets, each of which will possess the subnet mask: 255.255.254.0

So, Block size = (256-248) =8 (network size)

The subnets are:

Subnet 20: 180.180.64.0/21

Subnet 21: 180.180.72.0/21

Subnet 22: 180.180.80.0/21

Subnet 23: 180.180.88.0/21

We will assign 180.180.64.0/21 (subnet 20) as the network address for lan 2.

1^st valid host address for lan 2: 180.180.64.1/21.

Last valid host address for lan 2: 180.180.71.254/21.

e. Lan 3: 1000 hosts:

we will use subnet 21: 180.180.72.0/21 as the base address to subnet for supporting 1000 hosts. So, we have to borrow 1 bit from the host portion for such subnetting. There will be 2¹=2 subnets, each of which will possess the subnet mask: 255.255.252.0

So, Block size = (256-252) = 4 (network size).

Subnets are:

Subnet 210: 180.180.64.0/22

Subnet 211: 180.180.72.0/22

Now, we will assign 180.180.72.0/22 (subnet 210) as the network address for lan 3.

1^st valid host address for lan 3: 180.180.72.1/22.

Last valid host address for lan 3: 180.180.75.254/22.

f. Lan 6: 500 hosts:

We will use subnet 2111: 180.180.76.0/22 as the base address to subnet for supporting 500 hosts. So, we have to borrow 1 bit from the host portion for such subnetting. There will be 2¹=2 subnets, each of which will possess the subnet mask: 255.255.254.0

So, Block size = (256-254) = 2 (network size).

The subnets are:

Subnet 21110: 180.180.76.0/23

Subnet 21111: 180.180.78.0/23

Now, we will assign 180.180.76.1/23 (subnet 21110) as the network address for lan 6.

1^st valid host address for lan 6: 180.180.76.1/23.

Last valid host address for lan 6: 180.180.77.254/23.

g. Lan 7: 254 hosts:

We will use subnet 21111: 180.180.78.0/23 as the base address to subnet for supporting 500 hosts. So, we have to borrow 1 bit from the host portion for such subnetting. There will be 2¹=2 subnets, each of which will possess the subnet mask: 255.255.255.0

So, Block size = (256-255) = 1 (network size).

The subnets are:

Subnet 211110: 180.180.78.0/24

Subnet 211111: 180.180.79.0/24

Now, we will assign 180.180.78.0/24 (subnet 211110) as the network address for lan 7.

1^st valid host address for lan 7: 180.180.78.1/24.

Last valid host address for lan 7: 180.180.78.254/24.

h. Lan 8: 50 hosts:

We will use subnet 211111: 180.180.79.0/24 as the base address to subnet for supporting 50 hosts. So, we have to borrow 2 bits from the host portion for such subnetting. There will be 2² = 4 subnets, each of which will possess the subnet mask: 255.255.255.192.

So, Block size = (256-192) = 64 (network size).

The subnets are:

Subnet 2111110: 180.180.79.0/26

Subnet 2111111: 180.180.79.64/26

Subnet 2111112: 180.180.79.128/26

Subnet 2111113: 180.180.79.192/26

Now, we will assign 180.180.79.0/26 (subnet 2111110) as the network address for lan 8.

1^st valid host address for lan 8: 180.180.79.1/26.

Last valid host address for lan 8: 180.180.79.62/26.

Network address for WAN:

We will use subnet 2111111: 180.180.78.0/24 to support 2 valid addresses. So, we have to borrow 4 bits from the host portion for such subnetting. There will be 2⁴=16 subnets, each of which will possess the subnet mask: 255.255.255.252.

So, Block size = (256-252) = 4

a. 180.180.79.64/30

b. 180.180.79.68/30

c. 180.180.79.72/30

d. 180.180.79.76/30

e. 180.180.79.80/30

f. 180.180.79.84/30

g. 180.180.79.88/30

h. 180.180.79.92/30

i. 180.180.79.96/30

j. 180.180.79.100/30

k. 180.180.79.104/30

l. 180.180.79.108/30

m. 180.180.79.112/30

n. 180.180.79.116/30

o. 180.180.79.120/30

p. 180.180.79.124/30

We will assign:

a. 180.180.79.64/30 for network between Router A & Router B.

b. 180.180.79.68/30 network between Router B & Router C.

c. 180.180.79.72/30 network between Router A & Router C.

So, the resultant topology with network address will be:

Network address summary table:

Network Name		Network address	1st valid host		Last valid host
LAN 1		180.180.0.0/19	180.180.0.1/19		180.180.31.254/19
LAN 2		180.180.64.0/21	180.180.64.1/21		180.180.71.254/21
LAN 3		180.180.72.0/22	180.180.72.1/22		180.180.75.254/22
LAN 4		180.180.32.0/20	180.180.32.1/20		180.180.47.254/20
LAN 5		180.180.48.0/20	180.180.48.1/20		180.180.63.254/20
LAN 6		180.180.76.0/23	180.180.76.1/23		180.180.77.254/23
LAN 7		180.180.78.0/24	180.180.78.1/24		180.180.78.254/24
LAN 8		180.180.79.0/26	180.180.79.1/26		180.180.79.62/26
Network between Router A & Router B:		180.180.79.64/30	180.180.79.65/30		180.180.79.66/30
Network between Router B & Router C:		180.180.79.68/30	180.180.79.69/30		180.180.79.70/30
Network between Router A & Router C:	180.180.79.72/30		180.180.79.73/30	180.180.79.74/30