CCNA 2 Module 8 V3.1 Answers

1. Which layer protocols provide reliability for IP when needed?

ICMP and ping


upper layer protocols

lower layer protocols

Internet layer protocols

network access layer protocols


2. Which devices along a data transmission path are notified by ICMP when delivery failures occur?

source devices only

destination devices only

intermediary devices

source and destination devices

source, intermediary, and destination devices


3. Which of the following start the test of destination reachability?

echo request issued by source

echo reply issued by source

echo request issued by destination

echo reply issued by destination


4. How does ICMP improve data transfer reliability in IP networks?

Each router in the path reads ICMP packets and uses the information to update routing tables.

ICMP can correct many network problems as they occur.

ICMP error messages are returned to the sending device when a packet is dropped by a router.

ICMP packets report the intermediary devices that a packet passed through before failure occurred.


5. Which three conditions must be met in order for host to host communication over an internetwork to occur on IP networks? (Choose three.)

The routing protocols configured on the source and destination networks must be the same.

A default gateway must be properly configured on the hosts and local networks.

Intermediary devices, such as routers, must be present on the network and have knowledge of how to reach the destination network.

The source and destination host subnet masks must match.

The IP addresses of the hosts must be in the same network or subnet as their respective gateway devices.


6. When a datagram is processed by a router on the path from source to destination, what happens to the value in the TTL field?"

It is increased by one.

It is decreased by one.

It stays the same.

It is reset to 0.



7. Which condition could cause a fragmentation needed ICMP destination unreachable message to be sent?

A low bandwidth WAN link has become congested with IP traffic.

A packet is forwarded from a Token Ring network to an Ethernet network.

A network is not reachable because of faulty routing information.

The address specified by the sending host is nonexistent.



CCNA 2 Module 8 V3.1 Answers (1)
Workstation 1 sent a data packet to Workstation 4. It never arrived because Fa0/0 interface went down on Router C. How will the devices handle this failure?

Workstation 4 will send an error message to Router C and Workstation 1 that it did not receive the packet.

Router C will use ICMP to send a message back to Workstation 1 indicating that the packet could not be delivered.

Router C discards the packet without providing notification to any device.

Router C uses ICMP to correct the failure and transmits the data to Workstation 4.

Workstation 1 will use ICMP to correct the problem and then notify Router C to continue the transmission.


9. Which two statements are true regarding ICMP? (Choose two.)

ICMP provides reliability for the TCP/IP protocol stack.

ICMP is a component of the TCP/IP protocol stack.

ICMP notifies the sender that data transmission errors have occurred.

ICMP is connection-oriented.

ICMP messages are propagated to all intermediate devices.


10. Which type of message is generated by a host when the ping command is entered?

ICMP echo request

ICMP echo reply

UDP echo request

UDP error message


11. How does a source host use ICMP to confirm that a destination host is reachable?

The source host sends an ICMP echo request to the destination router which responds with an ICMP echo reply confirming the reachability of the destination host.

The source host sends a data packet and receives an ICMP host unreachable packet from the destination host if the data packet cannot be delivered.

The source host sends an ICMP packet with a TTL value of 1 and receives an ICMP reply with a TTL value of 0 from the destination host.

The source host sends an ICMP echo request and receives an ICMP echo reply from the destination host.

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