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 a 0 bit, that address is Class A. If it
begins with bits 10 then that address is a Class B address. If it begins with
110, 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?
Gateways
provide connectivity between two or more network segments. It is usually a
computer that runs the gateway software and provides translation services. This
translation is a key in allowing different systems to communicate on the
network.
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
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
– 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
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 is
required because at switch level there is only one broadcast domain, it means
whenever new user is connected to switch this information is spread throughout
the network. VLAN on switch helps to create separate broadcast domain at
switch level. It is used for security purpose.
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.
nice answer
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