Basic CCENT slides for for exam ICDN1 (100-101)

1. Avishek Maitra
NETWORK AND SECURITY

2. Data Communication

4. Network
A network is a collection of multiple computer and
hardware devices that are connected together ,
either physically or logically , using special
hardware and software for the exchange of
information and resources.
Advantages of networking
Connectivity and communication.
Data Sharing.
Resource Sharing.

5. Network Criteria

6. Transmission Mode

7. Modes Of Communication

8. Network Classification

9. LAN (Local Area Network)
 Local Area Network (LAN)
 A local area network (LAN) is a
computer network that interconnects
computers in a limited area such as a
home, school, computer laboratory, or
office building using network media.

11. MAN ( Metropolitan Area Network)
 Man is network which interconnects
large computer networks in which
two or more computer are connected
across a campus or a city.
 Area coverage is 5 to 50km
diameter.
 This network uses wireless
infrastructure or optical fiber
connections .

12. WAN (Wide Area Network)

13. Bus Topology

14. Features of Bus Topology
 Bus topology is the cheapest and the most common method of networking
system where multiple nodes are connected in a single line using a single
cable.
 The data is transferred to the entire system from one end of the cable to other
. A break in the cable will make the signal bounce back and forth along the
cable , to stop the signal from bouncing a component called “terminator” is
placed at ends to absorb free signal.

15. Advantages Disadvantages
Advantages And Disadvantages Of
Bus Topology
 Failure of one station does not
effect others.
 Easy to implement and extend.
 Failure of one cable connections
can disable the entire network
 Difficult to administer or
troubleshoot.

16. Mesh Topology

17. Star Topology

18. Advantages And Disadvantages
Of Star Topology
 Advantages
 Easy to extend and
implement even in large
networks.
 The failure of non central
node will not have major
effect on the functionality of
the network.
 Security can be
implemented in the
hub/switch.
 Disadvantages
 Failure of the central node
can disable the entire
network.

19. Ring Topology

20. Advantages And Disadvantages
Of Ring Topology
 Advantages
 Data travel in one direction
at high speed.
 Using coaxial cable to
create a ring network the
service become much
faster.
 Disadvantages
 Numerous connection to
other slow down the
network activity.
 If one node fails the rest of
the network fails.

21. Networking Hardware
Network Interface Card
Hubs
Bridges
Switches
Routers
Gateways
Firewalls
Workstation
Server

22. HUB
 Hubs are generally called multipoint repeaters.
 It is the simplest network device for interaction and the central point
of connection in star topology.
 Now days hubs have been replaced by switches.

40. SWITCH
 A switch is used to connect device on a network.
 It works in data link layer of OSI model.
 A switch is more intelligent than a hub ,as it forwards traffic to
destination MAC address ,rather than broadcasting messages to each
port.
 Uses full duplex technology i .e multiple device can communicate
simultaneously.
 Micro segmentation is possible in switches.
 Bandwidth is used efficiently as the frames are nor broadcast to all the
ports and hence secured than hubs.
 Operates at frame level.

41. Bridge
 A Bridge is a physical unit with 2 ports which connects 2
similar network segments together.
 a Bridge contains mac address and corresponding port
address.

42. NETWORK INTERFACE
CARD

43. FUNCTION OF NIC CARD
 Also known as network card/ Lan adapter card.
 It gives physical address or the mac address.
 It works in the data link layer of osi model.

45. ROUTER
 A router connects two or more (different) networks together and routes
packets of data from one network to another.
 A router runs a software that allows device to move data from one network
to other network.
 Router operates in network layer.
 It restricts network broadcast to lan.
 Act as a default gateway.
 Path selection .
 It communicates at packet level.

46. Router Diagram

47. BRIDGE VS ROUTER
• Bridge works at layer 1 and 2 of
osi model.
• A bridge recognizes one path
between the networks.
• A bridge works at mac layer by
looking at the destination
address and forwarding the
frame to appropiate segment.
• A bridge generally connects two
same networks.
 Router works at layer 3 of osi model.
 A router search among multiple
paths and determine the best path
for the particular packet.
 A router works with routing protocols
it filters address .It forward particular
data to particular address or to other
router.
 A router connects two different
networks.

48. IMPORTANT PROTOCOLS THAT USES TCP
AND UDP ALONG WITH THERE PORT
NUMBERS:
 TCP
 Telnet 23
 SMTP 25
 HTTP 80
 FTP 20 and 21
 DNS 53
 HTTPS 443
 SSH 22
 POP3 110
 NTP 123
 IMAP4 143
 UDP
 SNMP 161
 TFTP 69
 DNS 53
 DHCP 67

49. FIREWALL
 A firewall is a piece of software or hardware ,which will filter network traffic
between a computer , home network , or a company network.
 There are mainly 4 types of firewall
 packet filtering firewall
 proxy server
 Personal or local firewall
 Application gateway

50. SERVER
 A server provides resources to the clients on the network.
 Servers are typically powerful computers that runs a operating system that
controls and maintains the network.
 Severs are usually a specialized for a single purpose.
 Examples of server
 File server FTP server
 Print server proxy server
 Fax server mail server
 Web server
 Chat server

51. GATEWAY
 Gateways are task specific that performs protocol conversion
between different types of networks and applications
 The main features of the gateway is that it performs the
function of translating the data from one format to other
format

52. BROADCAST VS UNICAST VS
MULTICAST

53. OSI MODEL
 Also known as open source interconnection.
 Developed by ISO (International Standards ORGANIZATION)
 It is an architecture which divides network communication into seven
layers.
 Each layer covers different network activities , equipments and
protocols and has its own functions.
 The protocols help the other systems to communicate with each other

55. TCP VS UDP
 Transmission control protocol
 It is connection oriented protocol
 Acknowledgement segments.
 It establishes connection
between the two nodes , transfer
information , acknowledges the
other end of the station to know
data is receiving ensures that
packets are delivered error free.
 HTTP, HTTPs, FTP, SMTP
,TELNET
 User datagram protocol
 It is connectionless protocol
 No acknowledgement
 No initial connection is
established between the two
end points .The device transmits
the data from one end to the
other end without ensuring that
recipient is prepared to receive
the data.
 DNS, DHCP, TFTP, SNMP, RIP,

56. TCP/IP
 TCP/IP is the most popular protocol stack, which consist of large no of
protocol. According to the OSI model TCP/IP consist of only four layers.
TCP/IP model is modified form of DOD (Department of Defense)
model.
TCP/IP enables cross-platform or hetrogeneous , networking and
has following characteristics:
 Good failure recovery
 High error rate handling
 Platform independence
 Low data rate
 The ability to add network without interrupting existing service

57. TCP/IP LAYERS

58. WIRELESS ACCESS POINT
(WAP)

60. DNS
 DNS stands for (Domain Name Service/System/Server).
 Computer and other device communicate with IP address to identify each
other on the network.
 People do not remember IP address they use words to remember
www.google.com
www.europa.eu
 The domain name system is a TCP/IP standard that resolves IP address
to user friendly names and vice versa and gets you to your destination.
www.google.com 209.85.129.183
www.europa.com 147.67.119.102

61. DNS Name Resolution

62. DNS cont
 DNS service relies on 13 computers also known as root servers which act
as top level authority.
 There are mainly 3 components of DNS service
Resolver
Name servers
Name space
 Resolver is any host on internet that needs domain name information
 A name server/DNS server that has the database of names and their
associated IP address . If one name server cannot map the domain name
of its IP address ,the query is passed on to a name server with higher
authority.
 Name space refers to the database of IP address and corresponding
domain.

63. ARP/RARP
 Address Resolution Protocol is used to map an IP address with its
corresponding MAC address on a LAN.
 ARP cache is a table used to maintain a correlation between MAC and its
corresponding IP address.
 The reverse ARP performs the reverse steps of ARP . It uses the MAC
address to determine the devices IP address.
 RARP was originally developed foe diskless workstation to obtan their IP
address from a server.

64. MAC Address
 Media Access Control or MAC address is a hardware address which
uniquely identifies each node of a network.
 It is 12 bit hexadecimal number.
 Format of MAC address
 MM:MM:MM:SS:SS:SS
 MM-MM-MM-SS-SS-SS
 MAC address generally functions at the data link layer.

66. IP Addressing
 IP address is a unique number used to identify a computer and
communicate with each other on a network.
 IP address is 32 bit value which is divided into 8 bits field called octet.
 The IP address range from 1.0.0.0 to 255.255.255.255
 There are 2 parts of IP address
Network Address
Host Address

67. Why IP Addressing?
 An IP address serves two principal functions: host or network
interface identification and location addressing. Its role has been
characterized as follows: "A name indicates what we seek. An address
indicates where it is. A route indicates how to get there."[
 The Internet Assigned Numbers Authority (IANA) manages the IP address
space allocations globally.
 Computer uses IP address to locate and talk to each other on the tnternet
, much the same way people use phone number to locate and talk to one
another.

68. IP Addressing Methods
 There are 3 types of addressing methods
Static IP Address
Dynamic IP Address
APIPA(Automatic IP Addressing)
 Static IP Addressing
Static IP Addressing is done manually it is called permanent IP addressing
and it is given to user.
Static IP addressing do not require a DHCP server , we have to manually
configure IP , subnet and default gateway.

69. IP Addressing cont
Dynamic IP Addressing
 In dynamic IP addressing DHCP server automatically assigns IP , Subnet
mask , DNS Server ,default gateway.
 When we click on obtain IP Address automatically in windows ,the node
sends a request to DHCP Server to assign a n IP address.
APIPA (Automatic IP Addressing)
 When DHCP server goes down or the connection to the server is lost the
computer assigns its own IP address in the range of 169.254.0.0,so that the
computer can still communicate in the LAN , when it regains connectivity from
DHCP it changes its address

70. DHCP DORA Process

107. UTP
STP
UTP VS STP
 Unshielded twisted pair
 UTP is the most common type of
cable today.
 IT has 4 pair of cable twisted
together.
 Wire are twisted together to
prevent Electromagnet
interference (crosstalk).
 Shielded Twisted Pair
 It has a metal shielding on top.
 The shielding provides
resistance to external EMI.
 STP is considered secure than
UTP

108. Cabling
 Ethernet Cabling can be done in 3 ways
Straight-through cable
Crossover cable
Rolled cable
 Straight-through cable are used to connect 2 different devices
Host to Switch/hub
Router to Switch/hub
 Crossover cable can be used o connect 2 similar devices
Switch to Switch
Hub to Hub
Host to Host

109. Cabling cont
 Rolled Cable is used to connect a host EIA-TIA 232 interface to a
router console serial communication Port.

110. Media Types

111. Cable Standards

112. Straight Cable and Cross Cable

113. Rolled Cable

114. Media Connectors