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1) What is a Link?
A link refers to the connectivity between two
devices. It includes the type of cables and protocols used in order for one
device to be able to communicate with the other.
2) What are the
layers of the OSI reference model?
There are 7 OSI layers: Physical Layer, Data
Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer
and Application Layer.
3) What is backbone
network?
A backbone network
is a centralized infrastructure that is designed to distribute different routes
and data to various networks. It also handles management of bandwidth and
various channels.
4) What is a LAN?
LAN is short for Local Area Network. It
refers to the connection between computers and other network devices that are
located within a small physical location.
5) What is a node
A node refers to a point or joint where a
connection takes place. It can be computer or device that is part of a network.
Two or more nodes are needed in order to form a network connection.
6) What are
routers?
Routers can connect two or more network
segments. These are intelligent network devices that store information in its
routing table such as paths, hops and bottlenecks. With this info, they are
able to determine the best path for data transfer. Routers operate at the OSI
Network Layer.
7) What is point to
point link?
It refers to a direct connection between two
computers on a network. A point to point connection does not need any other
network devices other than connecting a cable to the NIC cards of both
computers.
8) What is
anonymous FTP?
Anonymous FTP is a
way of granting user access to files in public servers. Users that are allowed
access to data in these servers do not need to identify themselves, but instead
log in as an anonymous guest.
9) What is subnet
mask?
A subnet mask is combined with an IP address
in order to identify two parts: the extended network address and the host
address. Like an IP address, a subnet mask is made up of 32 bits.
10) What is the
maximum length allowed for a UTP cable?
A single segment of UTP cable has an
allowable length of 90 to 100 meters. This limitation can be overcome by using
repeaters and switches.
11) What is data
encapsulation?
Data encapsulation
is the process of breaking down information into smaller manageable chunks
before it is transmitted across the network. It is also in this process that
the source and destination addresses are attached into the headers, along with
parity checks.
12) Describe
Network Topology
Network Topology refers to the layout of a
computer network. It shows how devices and cables are physically laid out, as
well as how they connect to one another.
13) What is VPN?
VPN means Virtual Private Network, a technology that allows a secure
tunnel to be created across a network such as the Internet. For example, VPNs
allow you to establish a secure dial-up connection to a remote server.
14) Briefly
describe NAT.
NAT is Network Address Translation. This is a protocol that provides a
way for multiple computers on a common network to share single connection to
the Internet.
15) What is the job
of the Network Layer under the OSI reference model?
The Network layer is responsible for data
routing, packet switching and control of network congestion. Routers operate
under this layer.
16) How does a
network topology affect your decision in setting up a network?
Network topology dictates what media you must
use to interconnect devices. It also serves as basis on what materials,
connector and terminations that is applicable for the setup.
17) What is RIP?
RIP, short for
Routing Information Protocol is used by routers to send data from one network
to another. It efficiently manages routing data by broadcasting its routing table
to all other routers within the network. It determines the network distance in
units of hops.
18) What are different ways of securing a computer
network?
There are several
ways to do this. Install reliable and updated anti-virus program on all computers.
Make sure firewalls are setup and configured properly. User authentication will
also help a lot. All of these combined would make a highly secured network.
19) What is NIC?
NIC is short for Network Interface Card. This
is a peripheral card that is attached to a PC in order to connect to a network.
Every NIC has its own MAC address that identifies the PC on the network.
20) What is WAN?
WAN
stands for Wide Area Network. It is an interconnection of computers and devices
that are geographically dispersed. It connects networks that are located in
different regions and countries.
21) What is the
importance of the OSI Physical Layer?
The physical layer does the conversion from
data bits to electrical signal, and vice versa. This is where network devices
and cable types are considered and setup.
22) How many layers
are there under TCP/IP?
There are four layers: the Network Layer, Internet Layer,
Transport Layer and Application Layer.
23) What are proxy
servers and how do they protect computer networks?
Proxy servers primarily prevent external
users who identifying the IP addresses of an internal network. Without
knowledge of the correct IP address, even the physical location of the network
cannot be identified. Proxy servers can make a network virtually invisible to
external users.
24) What is the
function of the OSI Session Layer?
This layer provides the protocols and means
for two devices on the network to communicate with each other by holding a
session. This includes setting up the session, managing information exchange
during the session, and tear-down process upon termination of the session.
25) What is the
importance of implementing a Fault Tolerance System? Are there limitations?
A fault tolerance system ensures continuous
data availability. This is done by eliminating a single point of failure.
However, this type of system would not be able to protect data in some cases,
such as in accidental deletions.
26) What does
10Base-T mean?
The 10 refers to the data transfer rate, in
this case is 10Mbps. The word Base refers to base band, as oppose to broad
band. T means twisted pair, which is the cable used for that network.
27) What is a
private IP address?
Private IP addresses are assigned for use on
intranets. These addresses are used for internal networks and are not routable
on external public networks. These ensures that no conflicts are present among
internal networks while at the same time the same range of private IP addresses
are reusable for multiple intranets since they do not “see” each other.
28) What is NOS?
NOS, or Network Operating System, is
specialized software whose main task is to provide network connectivity to a
computer in order for it to be able to communicate with other computers and
connected devices.
29) What is DoS?
DoS, or Denial-of-Service attack, is an
attempt to prevent users from being able to access the internet or any other
network services. Such attacks may come in different forms and are done by a
group of perpetuators. One common method of doing this is to overload the
system server so it cannot anymore process legitimate traffic and will be
forced to reset.
30) What is OSI and
what role does it play in computer networks?
OSI (Open Systems Interconnect) serves as a
reference model for data communication. It is made up of 7 layers, with each
layer defining a particular aspect on how network devices connect and
communicate with one another. One layer may deal with the physical media used,
while another layer dictates how data is actually transmitted across the
network.
31) What is the
purpose of cables being shielded and having twisted pairs?
The main purpose of
this is to prevent crosstalk. Crosstalks are electromagnetic interferences or
noise that can affect data being transmitted across cables.
32) What is the
advantage of address sharing?
By using address
translation instead of routing, address sharing provides an inherent security
benefit. That’s because host PCs on the Internet can only see the public IP
address of the external interface on the computer that provides address
translation and not the private IP addresses on the internal network.
33) What are MAC
addresses?
MAC, or Media Access Control, uniquely
identifies a device on the network. It is also known as physical address or
Ethernet address. A MAC address is made up of 6-byte parts.
34) What is the equivalent layer or layers of
the TCP/IP Application layer in terms of OSI reference model?
The TCP/IP Application layer actually has
three counterparts on the OSI model: the Session layer, Presentation Layer and
Application Layer.
35) How can you
identify the IP class of a given IP address?
By looking at the
first octet of any given IP address, you can identify whether it’s Class A, B
or C. If the first octet begins with at 1 and end at 127, that address is Class A. If it
begins with at 128 and end at 191 then that address is a Class B address. If it begin at 192 and end at 223, then it’s a Class C network.
36) What is the
main purpose of OSPF?
OSPF, or Open Shortest Path First, is a link-state
routing protocol that uses routing tables to determine the best possible path
for data exchange.
37) What are
firewalls?
Firewalls serve to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can wipe out data in an instant. It also prevents other users from external networks from gaining access to the private network.
38) Describe star
topology
Star topology consists of a central hub that
connects to nodes. This is one of the easiest to setup and maintain.
39) What are
gateways?
40) What is the
disadvantage of a star topology?
One major disadvantage of star topology is
that once the central hub or switch get damaged, the entire network becomes
unusable.
41) What is SLIP?
SLIP, or Serial Line Interface Protocol, is
actually an old protocol developed during the early UNIX days. This is one of
the protocols that are used for remote access.
42) Give some
examples of private network addresses.
10.0.0.0 with a subnet mask of 255.0.0.0
172.16.0.0 with subnet mask of 255.240.0.0 192.168.0.0 with subnet mask of
255.255.0.0
43) What is
tracert?
Tracert is a Windows utility program that can
used to trace the route taken by data from the router to the destination
network. It also shows the number of hops taken during the entire transmission
route.
44) What are the
functions of a network administrator?
A network
administrator has many responsibilities that can be summarize into 3 key
functions: installation of a network, configuration of network settings, and
maintenance/troubleshooting of networks.
45) Describe at one
disadvantage of a peer to peer network.
When you are
accessing the resources that are shared by one of the workstations on the network,
that workstation takes a performance hit.
46) What is Hybrid
Network?
A hybrid network is a network setup that
makes use of both client-server and peer-to-peer architecture.
47) What is DHCP?
DHCP is short for
Dynamic Host Configuration Protocol. Its main task is to automatically assign
an IP address to devices across the network. It first checks for the next
available address not yet taken by any device, then assigns this to a network
device.
48) What is the
main job of the ARP?
The main task of ARP or Address Resolution
Protocol is to map a known IP address to a MAC layer address.
49) What is TCP/IP?
TCP/IP is short for Transmission Control Protocol / Internet Protocol.
This is a set of protocol layers that is designed to make data exchange
possible on different types of computer networks, also known as heterogeneous
network.
50) How can you
manage a network using a router?
Routers have built in console that lets you
configure different settings, like security and data logging. You can assign
restrictions to computers, such as what resources it is allowed access, or what
particular time of the day they can browse the internet. You can even put
restrictions on what websites are not viewable across the entire network.
51)
What protocol can be applied when you want to transfer files between different platforms,
such between UNIX systems and Windows servers?
Use FTP (File Transfer Protocol) for file
transfers between such different servers. This is possible because FTP is
platform independent.
52) What is the use
of a default gateway?
Default gateways provide means for the local
networks to connect to the external network. The default gateway for connecting
to the external network is usually the address of the external router port.
53)
One way of securing a network is through the use of passwords. What can be
considered as good passwords?
Good passwords are made up of not just
letters, but by combining letters and numbers. A password that combines uppercase
and lowercase letters is favorable than one that uses all upper case or all
lower case letters. Passwords must be not words that can easily be guessed by
hackers, such as dates, names, favorites, etc. Longer passwords are also better
than short ones.
54) What is the
proper termination rate for UTP cables?
The proper termination for unshielded twisted pair
network cable is 100 ohms.
55) What is
netstat?
Netstat is a command line utility program. It
provides useful information about the current TCP/IP settings of a connection.
56) What is the
number of network IDs in a Class C network?
For a Class C network, the number of usable Network ID bits is 21. The
number of possible network IDs is 2 raised to 21 or 2,097,152. The number of
host IDs per network ID is 2 raised to 8 minus 2, or 254.
57) What happens
when you use cables longer than the prescribed length?
Cables that are too long would result in
signal loss. This means that data transmission and reception would be affected,
because the signal degrades over length.
58) What common
software problems can lead to network defects?
Software related problems can be any or a combination of
the following:
–
client server problems
–
application conflicts
– error
in configuration
–
protocol mismatch
–
security issues
– user
policy and rights issues
59) What is ICMP?
ICMP is Internet Control Message Protocol. It
provides messaging and communication for protocols within the TCP/IP stack.
This is also the protocol that manages error messages that are used by network
tools such as PING.
60) What is Ping?
Ping is a utility program that allows you to
check connectivity between network devices on the network. You can ping a
device by using its IP address or device name, such as a computer name.
61) What is peer to
peer?
Peer to peer are networks that does not reply
on a server. All PCs on this network act as individual workstations.
62) What is DNS?
DNS is Domain Name
System. The main function of this network service is to provide host names to
TCP/IP address resolution.
63) What advantages
does fiber optics have over other media?
One major advantage of fiber optics is that
is it less susceptible to electrical interference. It also supports higher
bandwidth, meaning more data can be transmitted and received. Signal degrading
is also very minimal over long distances.
64) What is the
difference between a hub and a switch?
A hub acts as a multiport repeater. However,
as more and more devices connect to it, it would not be able to efficiently
manage the volume of traffic that passes through it. A switch provides a better
alternative that can improve the performance especially when high traffic
volume is expected across all ports.
65) What are the
different network protocols that are supported by Windows RRAS services?
There are three main network protocols supported:
NetBEUI, TCP/IP, and IPX.
66) What are the
maximum networks and hosts in a class A, B and C network?
For Class A, there are 126 possible networks and 16,777,214
hosts
For Class B, there are 16,384 possible networks and
65,534 hosts
For Class C, there are 2,097,152 possible networks and
254 hosts
67) What is the
standard color sequence of a straight-through cable?
orange/white,
orange, green/white, blue, blue/white, green, brown/white, brown.
68) What protocols
fall under the Application layer of the TCP/IP stack?
The following are the protocols under TCP/IP Application
layer: FTP, TFTP, Telnet and SMTP.
69)
You need to connect two computers for file sharing. Is it possible to do this
without using a hub or router?
Yes, you can
connect two computers together using only one cable. A crossover type cable can
be use in this scenario. In this setup, the data transmit pin of one cable is
connected to the data receive pin of the other cable, and vice versa.
70) What is
ipconfig?
Ipconfig is a utility program that is
commonly used to identify the addresses information of a computer on a network.
It can show the physical address as well as the IP address.
71) What is the
difference between a straight-through and crossover cable?
A straight-through
cable is used to connect computers to a switch, hub or router. A crossover
cable is used to connect two similar devices together, such as a PC to PC or
Hub to hub.
72) What is
client/server?
Client/server is a type of network wherein
one or more computers act as servers. Servers provide a centralized repository
of resources such as printers and files. Clients refers to workstation that access
the server.
73) Describe
networking.
Networking refers to the inter connection
between computers and peripherals for data communication. Networking can be
done using wired cabling or through wireless link.
74)
When you move the NIC cards from one PC to another PC, does the MAC address
gets transferred as well?
Yes, that’s because MAC addresses are
hard-wired into the NIC circuitry, not the PC. This also means that a PC can
have a different MAC address when the NIC card was replace by another one.
75) Explain clustering support
Clustering support
refers to the ability of a network operating system to connect multiple servers
in a fault-tolerant group. The main purpose of this is the in the event that
one server fails, all processing will continue on with the next server in the
cluster.
76) In a network that contains two servers
and twenty workstations, where is the best place to install an Anti-virus program?
An anti-virus
program must be installed on all servers and workstations to ensure protection.
That’s because individual users can access any workstation and introduce a
computer virus when plugging in their removable hard drives or flash drives.
77) Describe
Ethernet.
Ethernet is one of the popular networking technologies
used these days. It was developed during the early 1970s and is based on
specifications as stated in the IEEE. Ethernet is used in local area networks.
78) What are some
drawbacks of implementing a ring topology?
In case one workstation on the network
suffers a malfunction, it can bring down the entire network. Another drawback
is that when there are adjustments and reconfigurations needed to be performed
on a particular part of the network, the entire network has to be temporarily
brought down as well.
79) What is the
difference between CSMA/CD and CSMA/CA?
CSMA/CD, or Collision Detect, retransmits
data frames whenever a collision occurred. CSMA/CA, or Collision Avoidance,
will first broadcast intent to send prior to data transmission.
80) What is SMTP?
SMTP is short for Simple Mail Transfer
Protocol. This protocol deals with all Internal mail, and provides the
necessary mail delivery services on the TCP/IP protocol stack.
81) What is
multicast routing?
Multicast routing is a targeted form of
broadcasting that sends message to a selected group of user, instead of sending
it to all users on a subnet.
82) What is the
importance of Encryption on a network?
Encryption is the
process of translating information into a code that is unreadable by the user.
It is then translated back or decrypted back to its normal readable format
using a secret key or password. Encryption help ensure that information that is
intercepted halfway would remain unreadable because the user has to have the
correct password or key for it.
83) How are IP
addresses arranged and displayed?
IP
addresses are displayed as a series of four decimal numbers that are separated
by period or dots. Another term for this arrangement is the dotted decimal format.
An example is 192.168.101.2
84) Explain the
importance of authentication.
Authentication is the process of verifying a
user’s credentials before he can log into the network. It is normally performed
using a username and password. This provides a secure means of limiting the
access from unwanted intruders on the network.
85) What do mean by
tunnel mode?
This is a mode of data exchange wherein two
communicating computers do not use IPSec themselves. Instead, the gateway that
is connecting their LANs to the transit network creates a virtual tunnel that
uses the IPSec protocol to secure all communication that passes through it.
86) What are the
different technologies involved in establishing WAN links?
Analog connections
– using conventional telephone lines; Digital connections – using digital-grade
telephone lines; switched connections – using multiple sets of links between
sender and receiver to move data.
87) What is one
advantage of mesh topology?
In the event that one link fails, there will
always be another available. Mesh topology is actually one of the most
fault-tolerant network topology.
88)
When troubleshooting computer network problems, what common hardware-related problems
can occur?
A large percentage of a network is made up of
hardware. Problems in these areas can range from malfunctioning hard drives,
broken NICs and even hardware startups. Incorrectly hardware configuration is
also one of those culprits to look into.
89) What can be
done to fix signal attenuation problems?
A common way of dealing with such a problem
is to use repeaters and hub, because it will help regenerate the signal and
therefore prevent signal loss. Checking if cables are properly terminated is
also a must.
90) How does
dynamic host configuration protocol aid in network administration?
Instead of having to visit each client
computer to configure a static IP address, the network administrator can apply
dynamic host configuration protocol to create a pool of IP addresses known as
scopes that can be dynamically assigned to clients.
91) Explain profile
in terms of networking concept?
Profiles are the configuration settings made
for each user. A profile may be created that puts a user in a group, for
example.
92) What is
sneakernet?
Sneakernet is believed to be the earliest
form of networking wherein data is physically transported using removable
media, such as disk, tapes.
93) What is the
role of IEEE in computer networking?
IEEE, or the Institute of Electrical and
Electronics Engineers, is an organization composed of engineers that issues and
manages standards for electrical and electronic devices. This includes
networking devices, network interfaces, cablings and connectors.
94) What protocols
fall under the TCP/IP Internet Layer?
There are 4 protocols that are being managed by this
layer. These are ICMP, IGMP, IP and ARP.
95) When it comes
to networking, what are rights?
Rights refer to the
authorized permission to perform specific actions on the network. Each user on
the network can be assigned individual rights, depending on what must be
allowed for that user.
96) What is one
basic requirement for establishing VLANs?
A VLAN requires dedicated equipment on each
end of the connection that allows messages entering the Internet to be encrypted,
as well as for authenticating users.
97) What is IPv6?
IPv6 , or Internet
Protocol version 6, was developed to replace IPv4. At present, IPv4 is being
used to control internet traffic, butis expected to get saturated in the near
future. IPv6 was designed to overcome this limitation.
98) What is RSA
algorithm?
RSA is short for Rivest-Shamir-Adleman
algorithm. It is the most commonly used public key encryption algorithm in use
today.
99) What is mesh
topology?
Mesh topology is a setup wherein each device
is connected directly to every other device on the network. Consequently, it
requires that each device have at least two network connections.
100) what is the
maximum segment length of a 100Base-FX network?
The
maximum allowable length for a network segment using 100Base-FX is 412 meters.
The maximum length for the entire network is 5 kilometers.