You are a network technician at CertKing , Inc. You are required to troubleshoot a network connectivity
problem. While busy, you observe steady link lights on both the workstation NIC and the switch port to
which the workstation is connected. However, when the ping command is issued from the workstation,
the output message "Request timed out" is displayed.
At which layer of the OSI model does this problem reside?A. The data link layerB. The application layerC. The access layerD. The session layerE. The network layerAns: E

Explanation:
TCP/IP includes ICMP, a protocol designed to help manage and control the operation of a TCP/IP network. The
ICMP protocol provides a wide variety of information about a network's health and operational status. Control
message is the most descriptive part of a name. ICMP helps control and manage IP's work and therefore is
considered part of TCP/IP's network layer.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) page 277


Q76
The CertKing network is shown in the following exhibit:
What is the function of the Frame Relay DLCI with regard to CertKing 1?A. Defines the signaling standard between CertKing 1 and CertKing 2.B. Classifies the encapsulation used between CertKing 1 and CertKing 2.C. Identifies the circuit between CertKing 2 and the frame switch.D. Classifies the circuit between CertKing 1 and CertKing 2.E. Defines the signaling standard between CertKing 1 and the frame switch.Ans: C

Explanation:
CertKing 1 sends frames with DLCI, and they reach the local switch. The local switch sees the DLCI field and
forwards the frame through the Frame Relay network until it reaches the switch connected to CertKing 2. The
CertKing 2's local switch forwards the frame out of the access link to CertKing 2. DLCI information is
considered to be locally significant, meaning that the DLCI is used between the end router and the carrier's
local frame relay switch.
Reference: CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X)
Page 386
Incorrect Anss:
A, E. DLCI is used only as a circuit identifier (DLCI=Data Link Circuit Identifier), and not used for signaling.B. The encapsulation options are not defined with DLCIs.D. The DLCI information is considered to be locally significant, meaning that the DLCI is used between the
end router and the carrier's local frame relay switch. The DLCI is not used end to end (router to router).


Q77
You are a network technician at CertKing , Inc. A newly appointed trainee wants to know what the
purpose of DLCIs in Frame Relay is.
What would your response be?A. They determine the encapsulation type employed by the Frame Relay.B. They identify the logical circuit between a local router and a Frame Relay WAN switch.C. They represent the physical address of the router.D. They represent the keepalives in the maintenance of PVC.Ans: B

Explanation:
Routers use the data-link connection identifier (DLCI) as the Frame Replay address, which identifies the VC
over which the frame should travel.
Data Link Connection Identifiers are the "hardware address" on a Frame Relay network. They identify a routers
PVC to the Frame Relay switch.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) page 377
Incorrect Anss:A. DLCI information is not used to determine the encapsulation of the frame relay circuit in any way.C. A DLCI is used at layer two, but it is a separate identifier that is not related to the hardware MAC address of
any device.D. The function of a keepalive is handled by LMI in a frame network, not the DLCI.


Q78
The CertKing A router is configured as shown below:
CertKing A(config)# interface loopback 0
CertKing A(config-if)# ip address 192.168.16.24 255.255.255.255
As a result of this change, which of the statements below are true? (Select all valid responses)A. It creates a virtual, software only, interface.B. It provides a way to test the convergence of OSPF routing updates.C. The mask of 255.255.255.255 is called a host mask.D. It uses a wildcard mask of 255.255.255.255.E. It ensures that an interface is always active for OSPF processes.F. Loopback interfaces must be numbered 0.Ans: A, C, E

Explanation:
When the OSPF process starts, the Cisco IOS uses the highest local IP addresses its
OSPF router ID. If a loopback interface is configured, that address is used regardless of its value.
A loopback interface is a logical, software interface that is always up.
subnetwork.
Incorrect Anss:B. The addition of a loopback interface will in no way test the convergence speed of any OSPF process.D. A wildcard mask of value 255.255.255.255 will not check any of the bit values in the IP address.F. A loopback interface can be any number from 1-255.