Explanation:
HDLC and PPP Configuration
HDLC and PPP configuration is straightforward. You just need to be sure to configure the same WAN data-link
protocol on each end of the serial link. Otherwise, the routers will misinterpret the incoming frames, because
each WAN data-link protocol uses a different frame format. Other than configuring some optional features,
that's all you need to do.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 310


Q51
You are a network administrator at CertKing . The CertKing network is illustrated in the following
exhibit. Study it carefully:
You want to prevent users on the Research Network and the Internet from accessing the CertKing
Support server, but you want to allow all other CertKing users access to the server. You create an access
control list (ACL) called research block. The ACL contains the following statements:
deny 172.16.102.0 0.0.0.255 172.16.104.255 0.0.0.0
permit 172.16.0.0 0.0.255.255 172.16.104.252 0.0.0.0
Which of the following command sequence must be issued so that the list meets these requirements?A. CertKing 1(config)# interface e0
CertKing 1(config-if)# ip access-group research_block inB. CertKing 2(config)# interface s1
CertKing 2(config-if)# ip access-group research_block inC. CertKing 3(config)# interface s1
CertKing 3(config-if)# ip access-group research_block inD. CertKing 1(config)# interface s0
CertKing 1(config-if)# ip access-group research_block outE. CertKing 2(config)# interface s0
CertKing 2(config-if)# ip access-group research_block outF. CertKing 3(config)# interface e0
CertKing 3(config-if)# ip access-group research_block outAns: F

Explanation:
To enable the ACL on an interface and define the direction of packets to which the ACL is applied, the ip
access-group command is used.
When referring to a router, these terms have the following meanings.
o Out - Traffic that has already been through the router and is leaving the interface; the source would be
where it's been (on the other side of the router) and the destination is where it's going.
o In - Traffic that is arriving on the interface and which will go through the router; the source would be
where it's been and the destination is where it's going (on the other side of the router).
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 433
http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a00800a5b9a.shtml


Q52
You are a network administrator at CertKing . You are troubleshooting a router problem. You issue the
show ip route command on one of the routers. The output from the command is shown in the following
exhibit:
What does [120/3] represent?A. 120 is the bandwidth allocation and 3 is the routing process number.B. 120 is the administrative distance and 3 is the metric for that route.C. 120 is the value of the update timer and 3 is the number of updates received.D. 120 is the UDP port for forwarding traffic and 3 is the number of bridges.Ans: B

Explanation:
To decide which route to use, IOS uses a concept called Administrative Distance. Administrative distance is a
number that denotes how believable an entire routing protocol is on a single router. The lower the number, the
better, or more believable the routing protocol.
Route Type Administrative Distance
o Connected 0
o IGRP 100
o RIP 120
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 177


Q53
Which PPP authentication methods will you use when configuring PPP on an interface of a Cisco router?
(Select two options.)A. SSLB. SLIPC. PAPD. LAPBE. CHAPF. VNPAns: C E

Explanation:
Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP)
authenticate the endpoints on either end of a point-to-point serial link. Chap is the preferred method today
because the identifying codes flowing over the link are created using a MD5 one-way hash, which is more
secure that the clear-text passwords sent by PAP.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 314


Q54
Study the Exhibit below carefully:
What is the function of the Frame Relay DLCI with regard to CertKing A?A. Defines the signaling standard between CertKing A and CertKing B,B. Identifies the type of encapsulation in operation between CertKing A and CertKing B.C. Identifies the circuit between CertKing B and the frame switch.D. Defines the signaling standard between CertKing A and the frame switch.Ans: C

Explanation:
CertKing A 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 B. The
CertKing B's local switch forwards the frame out of the access link to CertKing B.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 386


Q55
You are a network technician at CertKing . The CertKing network is illustrated in the following exhibit.
Study it carefully:
Note: SPIDs are not required for this switch.
Which of the following command will you use to bring up the ISDN link? (Select three options.)A. Router(config-if)# encapsulation pppB. Router(config)# dialer-list 1 protocol ip allowC. Router(config)# isdn switch-type typeD. Router(config)# dialer map ip address name connection numberE. Router(config-if)# dialer-group 1F. Router(config-if)# ip address address subnet maskAns: B E F