You Can prepare 10 most asked questions.
Question:
1
Which
three statements are true about the operation of a full-duplex Ethernet
network? (Choose three.)
A.
There are no collisions in full-duplex mode.
B.
A dedicated switch port is required for each full-duplex node.
C.
Ethernet hub ports are preconfigured for full-duplex mode.
D.
In a full-duplex environment, the host network card must check for the
availability of the network media before transmitting.
E.
The host network card and the switch port must be capable of operating in
full-duplex mode.
Answer:
A, B, E
Explanation:
Half-duplex
Ethernet is defined in the original 802.3 Ethernet and Cisco says you only use
one wire pair with a digital signal running in both directions on the wire. It
also uses the CSMA/CD protocol to help prevent collisions and to permit
retransmitting if a collision does occur. If a hub is attached to a switch, it
must operate in half-duplex mode because the end stations must be able to
detect collisions. Half-duplex Ethernet—typically 10BaseT—is only about 30 to
40 percent efficient as Cisco sees it, because a large 10BaseT network will
usually only give you 3- to 4Mbps—at most.
Full-duplex
Ethernet uses two pairs of wires, instead of one wire pair like half duplex.
Also, full duplex uses a point-to-point connection between the transmitter of
the transmitting device and the receiver of the receiving device, which means
that with full-duplex data transfer, you get a faster data transfer compared to
half duplex. And because the transmitted data is sent on a different set of
wires than the received data, no collisions occur. The reason you don’t need to
worry about collisions is because now Full-duplex Ethernet is like a freeway
with multiple lanes instead of the single-lane road provided by half duplex.
Full-duplex Ethernet is supposed to offer 100 percent efficiency in both
directions; this means you can get 20Mbps with a 10Mbps Ethernet running full
duplex, or 200Mbps for FastEthernet.
Question:
2
DRAG
DROP
On
the left are various network protocols. On the right are the layers of the
TCP/IP model. Assuming a reliable connection is required, move the protocols on
the left to the TCP/IP layers on the right to show the proper encapsulation for
an email message sent by a host on a LAN. (Not all options are used.)
Answer:
Question:
3
Which
OSI layer header contains the address of a destination host that is on another
network?
A.
application
B.
session
C.
transport
D.
network
E.
data link
F.
physical
Answer:
D
Explanation:
Only
network address contains this information. To transmit the packets the sender
uses network address and datalink address. But the layer 2 address represents
just the address of the next hop device on the way to the sender. It is changed
on each hop. Network address remains the same.
Question:
4
Which
layer of the TCP/IP stack combines the OSI model physical and data link layers?
A.
Internet layer
B.
transport layer
C.
application layer
D.
network access layer
Answer:
D
Explanation:
The
Internet Protocol Suite, TCP/IP, is a suite of protocols used for communication
over the internet. The TCP/ IP model was created after the OSI 7 layer model
for two major reasons. First, the foundation of the Internet was built using
the TCP/IP suite and through the spread of the World Wide Web and Internet,
TCP/IP has been preferred. Second, a project researched by the Department of
Defense (DOD) consisted of creating the TCP/IP protocols. The DOD's goal was to
bring international standards which could not be met by the OSI model.
Since
the DOD was the largest software consumer and they preferred the TCP/IP suite,
most vendors used this model rather than the OSI. Below is a side by side
comparison of the TCP/IP and OSI models.
Question:
5
Which
protocol uses a connection-oriented service to deliver files between end
systems?
A.
TFTP
B.
DNS
C.
FTP
D.
SNMP
E.
RIP
Answer:
C
Explanation:
TCP
is an example of a connection-oriented protocol. It requires a logical
connection to be established between the two processes before data is
exchanged. The connection must be maintained during the entire time that
communication is taking place, then released afterwards. The process is much
like a telephone call, where a virtual circuit is established--the caller must
know the person's telephone number and the phone must be answered--before the
message can be delivered.
TCP/IP
is also a connection-oriented transport with orderly release. With orderly
release, any data remaining in the buffer is sent before the connection is
terminated. The release is accomplished in a three-way handshake between client
and server processes. The connection-oriented protocols in the OSI protocol
suite, on the other hand, do not support orderly release. Applications perform
any handshake necessary for ensuring orderly release.
Examples
of services that use connection-oriented transport services are telnet, rlogin,
and ftp.
Question:
6
Refer
to the exhibit.
If
the hubs in the graphic were replaced by switches, what would be virtually
eliminated?
A.
broadcast domains
B.
repeater domains
C.
Ethernet collisions
D.
signal amplification
E.
Ethernet broadcasts
Answer:
C
Explanation:
Modern
wired networks use a network switch to eliminate collisions. By connecting each
device directly to a port on the switch, either each port on a switch becomes
its own collision domain (in the case of half duplex links) or the possibility
of collisions is eliminated entirely in the case of full duplex links.
Question:
7
Refer
to the exhibit.
If
host A sends an IP packet to host B, what will the source physical address be
in the frame when it reaches host B?
A.
10.168.10.99
B.
10.168.11.88
C.
A1:A1:A1:A1:A1:A1
D.
B2:B2:B2:B2:B2:B2
E.
C3:C3:C3:C3:C3:C3
F.
D4:D4:D4:D4:D4:D4
Answer:
E
Explanation:
When
packets transfer from one host to another across a routed segment, the source IP
address always remains the same source IP address, and the source physical
(MAC) address will be the existing router’s interface address. Similarly, the
destination IP address always remains the same and the destination physical
(MAC) address is the destination router’s interface address.
Question:
8
Refer
to the exhibit.
HostX
is transferring a file to the FTP server. Point A represents the frame as it
goes toward the Toronto router. What will the Layer 2 destination address be at
this point?
A.
abcd.1123.0045
B.
192.168.7.17
C.
aabb.5555.2222
D.
192.168.1.1
E.
abcd.2246.0035
Answer:
E
Explanation:
For
packets destined to a host on another IP network, the destination MAC address
will be the LAN interface of the router. Since the FTP server lies on a
different network, the host will know to send the frame to its default gateway,
which is Toronto.
Question:
9
Which
network device functions only at Layer 1 of the OSI model?
A.
Option A
B.
Option B
C.
Option C
D.
Option D
E.
Option E
Answer:
B
Explanation:
Most
hubs are amplifying the electrical signal; therefore, they are really repeaters
with several ports. Hubs and repeaters are Layer 1 (physical layer) devices.
Question:
10
Refer
to the exhibit.
The
host in Kiev sends a request for an HTML document to the server in Minsk. What
will be the source IP address of the packet as it leaves the Kiev router?
A.
10.1.0.1
B.
10.1.0.5
C.
10.1.0.6
D.
10.1.0.14
E.
10.1.1.16
F.
10.1.2.8
Answer:
E
Although
the source and destination MAC address will change as a packet traverses a
network, the source and destination IP address will not unless network address
translation (NAT) is being done, which is not the case here.