Your CertKing trainee Bob asks you what 11111001 binary is in decimal. What should you tell him?A. 6B. 193C. 225D. 241E. 249Ans: E

Explanation:
128 + 64+32+16+8=1 = 249
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 559


Q46
You are a technician at CertKing . Your newly appointed CertKing trainee wants you to give her some
examples of crosstalk.
What would your reply be? (Choose all that apply.)A. near-end crosstalk (NEXT)B. jitter crosstalk (JEXT)C. far end crosstalk (FEXT)D. middle closed-end crosstalk (MCEXT)E. power sum near-end crosstalk (PSNEXT)Ans: A, C, E

Explanation: Near End Crosstalk (NEXT) is crosstalk measured at the transmitting end of the cable. Far
End Crosstalk (FEXT) is measured at the far end from where the signal was injected into the cable.
Power Sum NEXT (PSNEXT) is basically a mathematical calculation that simulates all four pairs being
energized at the same time. PSNEXT calculations are used to ensure that a cable will not exceed crosstalk noise
performance requirements when all pairs are operating simultaneously.
PSNEXT is typically used in Gigabit Ethernet, rather than 10BaseT or 100BaseT.
Reference: Sybex CCNA 4.0 - P. 30


Q47
You work as a network technician at CertKing . You are required to divide the 172.12.10.0 network into
subnets. Each subnet must have the capacity to support 458 IP addresses. You must provide the
maximum number of subnets.
Which network mask should you use?A. 255.255.224.0B. 255.255.240.0C. 255.255.248.0D. 255.255.252.0E. 255.255.254.0F. 255.255.255.0Ans: E

Explanation:
To obtain 458 IP addresses the number of host bits will be 9. In this maximum 512 hosts can be assigned. Keep
9 bits for host means 4th octet and last bit is 3rd will be 0. This gives 255.255.254.0 is subnet mask.


Q48
Which of the following factors determines the OSPF router ID when configuring a router with both
physical and logical interfaces?A. The lowest network number of any interface.B. The highest network number of any interface.C. The highest IP address of any logical interface.D. The middle IP address of any logical interface.E. The lowest IP address of any physical interface.F. The highest IP address of any physical interface.
G. The lowest IP address of any logical interface.Ans: F

Explanation:
The OSPF topology database includes information about routers and the subnets, or links, to which they are
attached. To identify the routers in the neighbor table's topology database, OSPF uses a router ID (RID) for
each router. A router's OSPF RID is that router's highest IP address on a physical interface when OSPF starts
running.
Note: The OSPF router ID is a 32-bit IP address selected at the beginning of the OSPF process. The highest IP
address configured on the router is the router ID. If a loopback address is configured, then it is the router ID. In
case of multiple loopback addresses, the highest loopback address is the router ID. Once the router ID is elected
it doesn't change unless the IP address is removed or OSPF restarts.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 208


Q49
Which of the following routes will be used to forward data in a situation where a routing table contains
static, RIP, and IGRP routes destined to the same network with each set to its default administrative
distance?A. The RIP routeB. The static routeC. The IGRP routeD. All three will load balance.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 Static 1
o IGRP 100
o RIP 120
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 177


Q50
You are a network administrator at CertKing . The CertKing network is illustrated in the following
exhibit. Study it carefully:
Routers CertKing 1 and CertKing 2 are connected through their social interfaces, however, they cannot
communicate. You ascertain that CertKing 1 has the correct configuration.
Can you identify the fault on router CertKing 2?A. Link reliability is insufficientB. IPCP is not openC. Incorrect subnet maskD. Incompatible encapsulationE. Bandwidth allocation is too lowF. Incomplete IP addressAns: D