1)
What are the differences among router, switch and
hub?
Hub (layer 1 Device):
§ Hubs,
also known as repeaters, are network devices that can operate on layer-1 (I.e.
the physical layer) to connect network devices for communication.
A
common connection point for devices in a network (Physical
Layer-Layer1). When a packet arrives at one port, it is copied to the
other ports so that all segments of the LAN can see all packets.
Switch (layer
2 Device)::
§ Switches
are network devices that operate on layer-2 of OSI model of communication.
§ Switches
are also known as intelligent hubs.
In networks, a device
that filters and forwards packets between LAN segments. Switches operate
at the data link layer (layer 2) and
sometimes the network layer(layer 3) of the
OSI Reference Model .
Router (layer 3 Device): :
§ Routers
are the network devices that operate at Layer-3 of OSI model of communication.
§ As
layer-3 protocols have access to logical address (IP addresses) so routers have
the capability to forward data across networks.
§ Sometimes
routers are also known as layer-3 switches.
A
device that forwards data packets along networks. A router is connected to
at least two networks, commonly two LANs or WANs or a LAN and its ISP [Network Layer (Layer3)]
2) a.What are the types of LAN cables used?
1.Straight Cable
2.Cross Cable
2)b.what is a cross cable?
Its
used to connect same type of devices without using a switch/hub so that they
can communicate.
3) What could be the maximum length of the LAN cable?
The theoretical length is 100 meters but after 80 meters you may see drop in speed due to loss of signal.
4) What would you use to connect two computers without using
switches?
Ans: Cross cable.
5)
What is IPCONFIG command? Why it is used?
IPCONFIG command is used to display the IP information assigned to a computer.
From the
output we can find out the IP address, DNS IP address, gateway IP address
assigned to that computer.
6) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
6) What is APIPA IP address? Or what IP address is assigned to the computer when the DHCP server is not available?
When DHCP
server is not available the Windows client computer assignes an automatic IP
address to itself so that it can communicate with the network cmputers. This ip
address is called APIPA. ITs in the range of 169.254.0.0 to 169.254.255.255
APIPA stands for Automatic private IP addressing.
APIPA stands for Automatic private IP addressing.
7) What is a
DOMAIN? What is the difference between a domain and a workgroup?
Domain is
created when we install Active Directory. It's a security boundary which is
used to manage computers inside the boundary. Domain can be used to centrally
administor computers and we can govern them using common policies called group
policies. We can't do the same with workgroup.
Domain: Collecton of clients controlled
by the server called Domain
Work Group : Colletion of Client network called
Work Group
8) What
is PING utility?
PING: Packet Internet
Gropper. It's a diagnostic
utility, which diagnose connectivitybetween computers. It use ICMP: Internet
Control Messaging protocol to send echorequests ( usually 4 packets) and
receive echo replies (4
packets)
9) What is the difference between physical address and logical
address?
Physical Address: It’s called as MAC Address
(48 bit)
Logical
Address : It’s Called as Ip Address (IPv4 -32 bit & IPv6 -128 bit)
10)What is the range of addresses in the classes of
internet addresses?
ClassA
: 1-126 N.H.H.H 1.0.0.1
to126.255.255.254 - 16 million hosts on each of 127 networks.
ClassB :
128 -191 N.N.H.H 1 28.1.0.1
to191.255.255.254 - 65,000 hosts on each of
16,000 networks.
ClassC: 192- 223 N.N.N.H 192.0.1.1 to223.255.254.254 - 254
hosts on each of 2 million networks.
ClassD : 224-239 -
Reserved for multicast groups.
Class
E: 240-254
- Reserved for
future use.
Ranges 127.x.x.x are
reserved for loopback or local host
Range of 169.254.X.X is APIPA,
stands for automatic private IP addressing
11)What is the difference between public and private IP addresses?
Public IP addresses
A
public IP address is
any valid address, or number, that can be accessed over the Internet.
Internet standards groups, such as the Network Information Center (NIC)
or the Internet Assigned Numbers Authority (IANA), are the organizations
responsible for registering IP ranges and assigning them to organizations, such
as Internet Service Providers (ISPs).
Private IP addresses
A private IP
address is any number or address assigned to a device on a private TCP/IP Local Area Network that is
accessible only within the Local Area Network. For a resource inside the
Local Area Network to be accessible over the Internet, a device within the
Local Area Network must be connected to the Internet with a public IP address,
and the networking must be appropriately configured.
The same
Internet standards organizations have reserved the following three IP address
ranges that will never be registered publicly:
|
First IP in block
|
Last IP in block
|
|
10.0.0.0
|
10.255.255.255
|
|
172.16.0.0
|
172.31.255.255
|
|
192.168.0.0
|
192.168.255.255
|
13) Crimping Types &
Colour Coding?
1.Straight
Crimping : Communication bw the
Difference Devices
Ex.( System To Switch & Switch to System or Modem)
2.Cross
Crimping : Communication bw the
same Devices
Ex.( System To system & Switch to switch)
|
Straight
|
|
|
1.
Orange
white orange
|
Orange white orange
|
|
2.
Green
white blue
|
Green white blue
|
|
3.
Blue
white green
|
Blue white green
|
|
4.
Brown
white Brown
|
Brown white Brown
|
|
Crosss
|
|
|
1.
Orange
white orange
|
Green white
Green
|
|
2.
Green
white blue
|
Orange white blue
|
|
3.
Blue
white green
|
Blue white Orange
|
|
4.
Brown
white Brown
|
Brown white
Brown
|
14)
What is a Gateway?
A
default gateway is a routing device used to forward all traffic that is not
addressed to a destination within the local network or local subnet. If you don’t
have a default gateway, it is not possible to communicate with the network
device/host of different networks
15)
What is Subnet Mask?
Subnet
mask is used for identify the Network.
Example:
For a
class A address, a standard subnet mask
is 255.0.0.0,
For a
class B address, a standard subnet mask
is 255.255.0.0,
For a
class C address, a standard subnet mask
is 255.255.255.0,
PORT NUMBERS:
|
Protocol PORT NUMBERS:
|
TCP/UDP
|
Port
Number
|
|
File Transfer Protocol (FTP)
|
TCP
|
20/21
|
|
Telnet
|
TCP
|
23
|
|
Simple Mail Transfer Protocol (SMTP)
|
TCP
|
25
|
|
Domain Name System (DNS)
|
TCP/UDP
|
53
|
|
Dynamic Host Configuration Protocol (DHCP)
|
UDP
|
67/68
|
|
Trivial File Transfer Protocol (TFTP)
|
UDP
|
69
|
|
Hypertext Transfer Protocol (HTTP)
|
TCP
|
80
|
|
Post Office Protocol (POP) version 3
|
TCP
|
110
|
|
NetBIOS
|
TCP/UDP
|
137/138/139
|
|
Internet Message Access Protocol (IMAP)
|
TCP
|
143
|
|
Simple Network Management Protocol (SNMP)
|
TCP/UDP
|
161/162
|
|
Hypertext Transfer Protocol over SSL/TLS (HTTPS)
|
TCP
|
443
|
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