Medi-Caps University Indore

Computer Network Lab File

Department Of Computer Science Engineering
Session: 2019-23

Submitted To: Submitted By:

Sonal Modh Ma’am Saksham Jain

EN19CS301316
CS-F
S.No Name Of Experiment Experiment Submission Remark
Date Date

1. Case study of different 16-08-21 23-08-21

types of cables

2. Connectors
3. Media Converter
4. Networking Commands
5. Installation of Cisco
Packet Tracer

6. Different Topologies in
Computer networks

7. DHCP configuration
8. Subnetting
9. Establishing a VLAN
Network

10. Establishing a Inter-

VLAN
 Experiment:- 1
Aim: Case study of different types of cables.

In data communication terminology, a transmission medium is a physical path between the transmitter and the
receiver i.e it is the channel through which data is sent from one place to another. Transmission Media is broadly
classified into the following types:  

Coaxial cable
Coaxial cable has long been the preferred form of cabling, for the simple reason that it’s cheap and easily handled (weight,
flexibility, ...).

A coaxial cable is made of up a central copper wire (called core) surrounded by an insulator and a braided metal shield.

The following image shows its structure:

 The jacket protects the cable from the external environment. It is usually made of rubber (or sometimes Polyvinyl
Chloride (PVC) or Teflon).

 The shield (metal envelope) surrounding the cables protects the data transmitted on the medium from interference (also
called noise) that could corrupt the data.

 The insulator surrounding the central core is made of a dielectric material that prevents any contact with the shield that
could cause electrical interactions (short circuit).

 The core, which actually transports the data, generally consists of a single copper strand or of several braided strands.
 Coaxial cable can be used over long distances at high speed (unlike twisted pair cable), however it is usually used for basic
installations.

Note that there are also coaxial cables that have a double shield (one insulating layer, one shield layer) and coaxial cables
with four shields (two insulating layers, two shield layers).

Normally, two types of coaxial cable are used:

 10Base2 - thin coaxial cable (called Thinnet or CheaperNet) is a thin cable (6 mm in diameter), that is white (or grayish)
by convention. It is very flexible and can be used in most networks by connecting it directly to the network card. It is able
to transport a signal up to around 185 metres without line loss.

It is part of the RG-58 family whose impedance (resistance) is 50 ohms. The different types of thin coaxial cables are
differentiated by the central part of the cable (core).

Cable Description
RG-58 / U Central core consisting of a single copper strand
RG-58 A/U Braided
RG-58 C/U Military version of RG-58 A/U
RG-59 Wide band transmission (cable television)
RG-6 Thicker diameter, recommended for higher frequencies than RG-
59
RG-62 Arcnet Network
 10Base5 - thick coaxial cable (Thicknet or Thick Ethernet and also called Yellow Cable, because of its yellow color - by
convention) is a shielded cable with a thicker diameter (12 mm) and 50 ohm impedance. It was used for a long time in
Ethernet networks, which is why it is also known as "Standard Ethernet Cable''. Given that it has a larger-diameter core,
it is able to carry signals over long distances: up to 500 meters without line loss (and without signal reamplification). It
has a bandwidth of 10 Mbps and is very often used as a backbone to connect networks whose computers are connected
with Thinnet. However, because of its diameter, it is less flexible than Thinnet.

Advantages:
 High Bandwidth
 Better noise Immunity
 Easy to install and expand
 Inexpensive

Disadvantages:
 Single cable failure can disrupt the entire network

Applications of Coaxial Cables

 In analog telephone networks: A single coaxial network can carry about 10,000 voice signals.
 In digital telephone networks: A coax has a data rate of 600 Mbps.
 In cable TV networks
 In traditional Ethernet LANs
 In MANs
 Twisted pair cabling
In its simplest form, twisted-pair cable consists of two copper strands woven into a braid and covered with insulation.

Reason for Twisting

All transmissions are prone to noise, interferences, and crosstalks. When the wires are twisted, some part of the noise signals
is in the direction of data signals while the other parts are in the opposite directions. Thus the external waves cancel out due
to the different twists. The receiver calculates the difference in the voltages of the two wires for retrieving data. Thus a much
better immunity against noise is obtained.

Two types of twisted pair cable are generally recognized:

 Shielded Twisted Pair (STP).

 Unshielded Twisted-Pair (UTP ).
A cable is often made of several twisted pairs grouped together inside a protective jacket. The twisting eliminates noise
(electrical interference) due to adjacent pairs or other sources (motors, relays, transformers).

Twisted pair is therefore suitable for a local network with few nodes, a limited budget and simple connectivity. However,
over long distances at high data rates it does not guarantee data integrity (i.e. loss-less data transmission).

Unshielded Twisted Pair (UTP)

UTP cable complies with the 10BaseT specification. This is the most commonly used twisted pair type and the most widely
used on local networks. Here are some of its characteristics:

 Maximum segment length: 100 metres.

 Composition: 2 copper wires covered with insulation.
 UTP Standards: determine the number of twists per foot (33 cm) of cable depending on the intended use.
 UTP: collected in the EIA/TIA (Electronic Industries Association / Telecommunication Industries Association)
Commercial Building Wiring Standard 568. The EIA/TIA 568 standard used UTP to create standards applicable to all
sorts of spaces and cabling situations, thereby guaranteeing the public homogeneous products. These standards include
five categories of UTP cables:

 Category 1: Traditional telephone cable (voice but no data transmission)

 Category 2: Data transmission up to a maximum of 4 Mbit/s (RNIS). This type of cable contains 4 twisted pairs

 Category 3: 10 Mbit/s maximum. This type of cable contains 4 twisted pairs and 3 twists per foot

 Category 4: 16 Mbit/s maximum. This type of cable contains 4 copper twisted pairs

 Category 5: 100 Mbit/s maximum. This type of cable contains 4 copper twisted pairs

 Category 5e: 1000 Mbit/s maximum. This type of cable contains 4 copper twisted pairs
Most telephone installations use UTP cable. Many buildings are pre-wired for this type of installation (often in sufficient
numbers to satisfy future requirements). If the pre-installed twisted pair is of good quality, it can be used to transfer data in
a computer network.

UTP's major problem is that it is particularly susceptible to interference (signals from one line mixing with those of
another line). The only solution to this is shielding.

Advantages: 
⇢ Least expensive
⇢ Easy to install
⇢ High-speed capacity
⇢ Susceptible to external interference
⇢ Lower capacity and performance in comparison to STP
⇢ Short distance transmission due to attenuation
Shielded Twisted Pair (STP)
STP (Shielded Twisted Pair) cable uses a copper jacket that is of better quality and more protective that the jacket used for
UTP cable. It contains a protective envelope between the pairs and around the pairs. In an STP cable, the copper wires of one
pair are themselves twisted, which provides STP cable with excellent shielding (in other words, better protection against
interference). It also allows faster transmission over a longer distance.

Advantages: 
⇢ Better performance at a higher data rate in comparison to UTP
⇢ Eliminates crosstalk
⇢ Comparatively faster
⇢ Comparatively difficult to install and manufacture
⇢ More expensive
⇢ Bulky

Uses of Twisted Pair Cables

All transmissions are done with crosstalk, interference, and noise. When wires are getting to twisted, then few parts of noise signals is in the direction of
data signals but other parts are flowing in the against direction. Due to different twists, it gets to cancel external waves. The receiver is capable to
manipulate the difference in the voltages of two wires for getting to fetch data. So, it gets better immunity opposite noise is obtained.

Optical fibre
A fibre optic cable is made of glass or plastic and transmits signals in the structure of light signals. The structure of an optical fibre
cable is displayed in the figure. It involves an inner glass core surrounded by a glass cladding that reflects the light into the core. Each
fibre is encircled by a plastic jacket.

In fibre optics, semiconductor lasers transmit data in the form of light along with hair-thin glass (optical) fibres at the speed of light
(186,000 miles second) with no significant loss of intensity over very long distances. The system includes fibre optic cables that are
made of tiny threads of glass or plastic.

Characteristics of Optical Fibre Cables

The main characteristics of Optical Fibre cables are as follows −

 Fibre optic cabling can support too high bandwidths in the range from 100 Mbps to 2 gigabytes because light has a much greater
frequency than electricity.

 The several nodes that a fibre optic can provide does not rely upon its length but on the hub or hubs that linked cables.

 Fibre optic cable is not concerned by EMI effects and can be used in locations where high voltages pass.

 The value of fibre optic cable is more distinguished to twisted pair and co-axial.

 The setup of fibre optic cables is complex and endless.

Types of Optical fibres

 Single-mode optical fiber
 Multimode optical fiber with stepped index
 Multimode optical fiber with graded-index
 Microstructured optical fibers are a new type of optical fibers that are different from the above three in a few areas. The core
difference is the way in which light is controlled in single/multimode fibers and microstructured optical fibers.

Advantages :

The advantage of optical fibre is as follows −

 Small Size and lightweight − The size (diameter) of the optical fibres is minimal (comparable to the diameter of a human hair).
 Easily available and low cost − The material used for producing the optical fibres is silica glass. This material is readily
applicable. Therefore, the optical fibres cost lower than the cables with metallic conductors.
 No electrical or electromagnetic interface − Since the transmission occurs in light rays, the signal is not affected by electrical or
electromagnetic interference.
 Large Bandwidth − As the light arrays have a very high frequency in the GHz range, the optical fibre bandwidth is vast. This
allows the transmission of more numbers of channels. Therefore, the information-carrying capacity of an optical fibre is much
higher than that of a Co-axial cable.

Disadvantages:
 Difficult to install and maintain
 High cost
 Fragile
 Comparison between twisted pair cables, coaxial cables and optical fiber cables:

CHARACTERISTICS TWISTED PAIR COAXIAL CABLE OPTICAL FIBER

CABLE CABLE
Signal Transmission Takes place in the Takes place in the Takes place in an
electrical form over electrical form over optical form over a
the metallic the inner conductor glass fiber.
conducting wires. of cable.
External Magnetic field Affected due to External magnetic External magnetic
external magnetic field is less affected. field is not affected.
field.
Cause of power Power loss due to Power loss due to Power loss due to
conduction and conduction. absorption, scattering
radiation. and bending.
Bandwidth It has low bandwidth. It has moderately It has very high
high bandwidth. bandwidth.
EMI EMI can take place. EMI is reduced to EMI is not present.
shielding.
Installation Easy installation. Fairly easy Difficult to install.
installation.
Attenuation It has very high It has low It has very low
attenuation. attenuation. attenuation.
Data Rate It supports low data It supports Very high data rate.
rate. moderately high data
rate.
Noise immunity Twisted pair cable Coaxial cable has Optical fibre cable
has low noise moderately high has highest noise
immunity. noise immunity. immunity.
Category 5 cable

Category 5 cable (Cat 5) is a twisted pair cable for computer networks. Since 2001, the variant commonly in use is
the Category 5e specification (Cat 5e). The cable standard provides performance of up to 100 MHz and is suitable for most varieties
of Ethernet over twisted pair up to 2.5GBASE-T but more commonly runs at 1000BASE-T (Gigabit Ethernet) speeds. Cat 5 is also used to
carry other signals such as telephone and video.
This cable is commonly connected using punch-down blocks and modular connectors. Most Category 5 cables are unshielded, relying on
the balanced line twisted pair design and differential signaling for noise rejection.

Standards
The cable is available in both stranded and solid conductor forms. The stranded form is more flexible and withstands more bending without
breaking. Patch cables are stranded. Permanent wiring used in structured cabling is solid-core. The category and type of cable can be
identified by the printing on the jacket.
The category 5 specification requires conductors to be pure copper. The industry has seen a rise in non-compliant / counterfeit cables,
especially of the Copper Clad Aluminum (CCA) variety. This has exposed the manufacturers or installers of such fake cable to legal
liabilities.

Applications
Category 5 cable is used in structured cabling for computer networks such as Ethernet over twisted pair. The cable standard prescribes
performance parameters for frequencies up to 100 MHz and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), 1000BASE-
T (Gigabit Ethernet), 2.5GBASE-T, and 5GBASE-T. 10BASE-T and 100BASE-TX Ethernet connections require two wire pairs.
1000BASE-T and faster Ethernet connections require four wire pairs. Through the use of  power over Ethernet (PoE), power can be carried
over the cable in addition to Ethernet data.

Characteristics
Property Nominal Tolerance Unit
Characteristic impedance, 1–100 MHz 100 ± 15 Ω
Characteristic impedance @ 100 MHz 100 ±5 Ω
DC loop resistance ≤ 0.188 Ω/m
Propagation speed relative to the speed of
0.64 1
light
Propagation delay 5.30 ns/m
Delay skew < 100 MHz < 0.20 ns/m
Capacitance at 800 Hz 52 pF/m
Max tensile load, during installation 100 N
Wire diameter (24 AWG; 0.205 mm )) 2
0.51 mm
Operating temperature −55 to +60 °C
Maximum DC operating voltage 125 V
 (PoE uses max 57 V)

Category 6 cable

Category 6 cable (Cat 6), is a standardized twisted pair cable for Ethernet and other network physical layers that is backward

compatible with the Category 5/5e and Category 3 cable standards.
Cat 6 must meet more stringent specifications for crosstalk and system noise than Cat 5 and Cat 5e. The cable standard specifies
performance of up to 250 MHz, compared to 100 MHz for Cat 5 and Cat 5e. [1]

Whereas Category 6 cable has a reduced maximum length of 55 metres (180 ft) when used for 10GBASE-T, Category 6A cable is
characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100-metre (330 ft)
maximum distance as previous Ethernet variants.

Description
Cat 6 cable can be identified by the printing on the side of the cable sheath. [3] Cable types, connector types and cabling topologies are
defined by ANSI/TIA-568.
Cat 6 patch cables are normally terminated in 8P8C modular connectors, using either T568A or T568B pin assignments; performance is
comparable provided both ends of a cable are terminated identically.
If Cat 6-rated patch cables, jacks and connectors are not used with Cat 6 wiring, overall performance is degraded and may not meet Cat 6
performance specifications.[4]
The category 6 specification requires conductors to be pure copper. The industry has seen a rise in non-compliant / counterfeit cables,
especially of the Copper Clad Aluminum (CCA) variety. [5] This has exposed the manufacturers or installers of such fake cable to legal
liabilities.

Differences between Cat5 And Cat6 Cable

There are many differences between CAT5 and CAT6 cables; such as performance, type of cable, type of jacket and cost, among others.

When choosing which one to use, one must first consider the amount of bandwidth the cable must support. CAT5 can support up to 10/100
Mbps at a 100MHz bandwidth. However, a newer version of CAT5 cable in the market, CAT5e, can support up to 100/1000 Mbps at a
350MHz bandwidth. In comparison, CAT6 can support up to 1000 Mbps (1GbE) at a 250MHz bandwidth. Better yet, a newer version of
CAT6 that Cablesys offers can support up to 1GbE at a 500MHz bandwidth.

Another major factor that influences the performance is the amount of twist a cable has. While CAT5e cable features one and a half to two
twists per centimeter, CAT6 cables are more tightly wound and feature two or more twists per centimeter.

A third aspect is the overall diameter of the cable. Airflow is a major consideration in the data center. As more cable is added to the
patching area, it will restrict airflow needed to cool the servers and equipment. CAT6 cable has a thicker diameter around 0.250-inches
maximum while CAT5e cable has a smaller diameter around 0.204-inches.

Finally, another major difference is their cost. The price varies by length and brand. In general, CAT6 cables are about 10% to 20% more
expensive compared to CAT5e cables. Cablesys offers the best selling cables. Prices can be compared on Cablesys’ website;  CAT5e
cables versus CAT6 cables , and CAT5e patch cables versus CAT6 patch cables.
 Experiment -2
Connectors
A device that eliminates a section of cabling or implements a state of access for network devices, including PCs, hubs, and switches.
Connectors can be famous for their physical presentation and mating features, including jacks and attachment (male connectors) or
attachments and ports (female connectors).

RJ-11 connector: A 4-wire or 6-wire telephone-type connector that connects telephones to wall plates. RJ-11 supports up to six wires, but
usually only four are used with the two-pair twisted-pair cabling commonly found in telephone cabling.

RJ-11 Pin Signal Name

1 VCC (5 volts regulated)

2 Power Ground

3 One Wire Data

4 One Wire Ground

RJ-45 connector: An 8-wire telephone-type connector used with twisted-pair cabling for connecting computers, wall plates, patch panels,
and other networking components. RJ-45 is the standard type of connector for both unshielded twisted-pair (UTP) and shielded twisted-pair
(STP) cabling in star-topology Ethernet networks such as 10BaseT and 100BaseT4. RJ-45 is defined in International Organization for
Standardization (ISO) standard 8877.

 
1. SC Connector

The SC was developed by the laboratories at Nippon

Telegraph and Telephone  (NTT) in the mid-eighties,
and was one of the first connectors to hit the market
following the advent of ceramic ferrules. Sometimes
referred to as the ‘square connector’ the SC has a
push-pull coupling end face with a spring loaded
ceramic ferrule. Initially intended for Gigabit Ethernet
networking, it was standardized into the
telecommunications specification TIA-568-A in 1991 and slowly grew in popularity as manufacturing costs came
down. Due to its excellent performance it dominated fiber optics for over a decade with only the ST rivalling it.
Thirty years on, it remains the second most common connector for polarization maintaining applications. The SC
is ideally suited for datacoms and telecoms applications including point to point and passive optical networking.

2. LC Connector

Considered by some to be the modern replacement of

the SC connector; its introduction was less successful,
in part due to initially high license fees from inventor
Lucent Corporation. Also a push-pull connector, the
LC utilizes a latch as opposed to the SC locking tab
and with a smaller ferrule it is known as a small form
factor connector. Having half the footprint of the SC
connector gives it huge popularity in datacoms and
other high-density patch applications, as its combination of small size and latch feature make it ideal for densely
populated racks/panels. With the introduction of LC compatible transceivers and active networking components,
its steady growth in the FTTH arena is likely to continue.
SFP(Small Form-factor Pluggable)
SFP (Small Form-factor Pluggable) module connector with various data speed rate is one of the
major optical transceivers used for data communication. With ever-increasing demand for faster speed
and higher density, the SFP connectors have experienced several generations of update for the signal
speed capability as well as port density, from the original SFP to SFP+ and then to the new SFP28 type.
The compatibility of these connecting ports is the pain point for many subscribers in data communication
transmission.

LIU(Light Interface Unit)

The Light Interface Unit is used in for routing, and managing optical cable terminations. The outer body is made
of quality steel with anti corrosive powder coating. It incorporates communication between various system inputs
and outputs related to lighting control with the use of central computing devices. A wide range of Fiber optic
Light Interface Unit is offered by our organization. It is easy to maintain and access as it consumes less space.
 Experiment -3
Media Converter
A media converter is a networking device that transparently converts Ethernet or other communication protocols
from one cable type to another type, usually copper CATx/UTP to fibre. Media converters are often used in pairs
to insert a fibre segment into copper networks to increase cabling distances and enhance immunity to
electromagnetic interference. They can also extend LANs, and convert link speeds and fibre modes.

Benefits of Media Converters

 Extend LAN Distance with Fibre

 Copper-based Ethernet connections are limited to a data transmission distance of 100 metres when using
UTP cable. By using Ethernet to fibre conversion, you can extend link distance up to 80 kilometres or
more.
 Maintain Investments in Existing Equipment
 Protect Data from Interference
 Speed Conversion
 Power over Ethernet

Types of Media Converters

1. Copper-to-Fibre Media Converters

Copper-to-fibre media converters enable connections of copper-based Ethernet equipment over a fibre
optic link. This extends links over greater distances with fibre optic cable, protects data from noise and
interference, and future-proofs a network with additional bandwidth capacity.

2. Fibre-to-Fibre Media Converters

Fibre-to-fibre media converters connect different fibre optic networks and support conversion from one
wavelength to another. They provide connectivity between single-mode and multimode fibre, as well as
between dual and single fibre.

3. PoE Media Converters

Power-over-Ethernet (PoE) media converters provide reliable and cost-effective fibre distance extension
to PoE-powered devices. PoE media converters can power devices like IP phones, videoconferencing
equipment, IP cameras and Wi-Fi devices over copper UTP cabling.

4. Stand-Alone vs. Chassis-Based Media Converters

Stand-alone media converters are compact and can be AC or DC powered. They are commonly used to
convert one copper link to fibre in point-to-point installs. These converters are easy to deploy and offer a
range of useful functionality for your network, such as auto-MDI/MDIX, link fault pass through and
more.

 
Layer 2 switching
Layer 2 switching (or Data Link layer switching) is the process of using devices’ MAC addresses to decide where to forward
frames. Switches and bridges are used for Layer 2 switching. They break up one large collision domain into multiple smaller
ones.

In a typical LAN, all hosts are connected to one central device. In the past, the device was usually a hub. But hubs had many
disadvantages, such as not being aware of traffic that passes through them, creating one large collision domain, etc. To
overcome some of the problems with hubs, bridges were created. They were better than hubs because they created multiple
collision domains, but they had limited number of ports. Finally, switches were created and are still widely used today.
Switches have more ports than bridges, can inspect incoming traffic and make forwarding decisions accordingly. Also. each
port on a switch is a separate collision domain, so no packet collisions should occur.

Layer 2 switches are faster than routers because they don’t take up time looking at the Network layer header information.
Instead, they look at the frame’s hardware addresses to decide what to do with the frame – to forward, flood, or drop it. Here
are other major advantages of Layer 2 switching:

 fast hardware-based bridging (using ASICs chips)

 wire speed
 low latency
 low cost

Wireless access point

In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking
hardware device that allows other Wi-Fi devices to connect to a wired network. As a standalone device, the AP
may have a wired connection to a router, but, in a wireless router, it can also be an integral component of the
router itself. An AP is differentiated from a hotspot which is a physical location where Wi-Fi access is available.
An AP connects directly to a wired local area network, typically Ethernet, and the AP then provides wireless
connections using wireless LAN technology, typically Wi-Fi, for other devices to use that wired connection. APs
support the connection of multiple wireless devices through their one wired connection.

Modem
A cable modem is a hardware device that uses a coax cable to connect your computer devices with your Internet
service provider (ISP). A cable modem connects to the Internet.
There are a few different types of modems: analog modems (dial-up), digital subscriber line (DSL) or cable
modems.   Typically, your Internet Service Provider (ISP) rent modems to their subscribers, that can come with
some added benefits.  The option to buy or purchase your own modem can save you from paying monthly rental
fees (sometimes up to $150 per year* depending on your current rental fees).  Your modem will give you a
reliable, wired Internet connection.  If you only have one device that needs to connect to the Internet, like a PC or
laptop, you can get away with just having a modem. But if you have multiple devices, or want to use your devices
wirelessly (WiFi), then you will need a router, too.

Router
A cable modem router (sometimes called a gateway) connects to the Internet and distributes the internet
connection to multiple devices (like a router does).
It comes down to your preference for your home network setup. A combo cable modem router can serve you well.
However, if you want more freedom to adjust things on your home network, like security settings, you might want
to have a separate cable modem and router. To have even more freedom, you can purchase your own cable
modem, router, or cable modem router instead of renting them for a monthly fee. This can save you money over
time, however, renting from your ISP can come with access to technicians and troubleshooting as well.
Layer 3 Switch
Simply put, a layer 3 switch combines the functionality of a switch and a router. It acts as a switch to connect
devices that are on the same subnet or virtual LAN at lightning speeds and has IP routing intelligence built into it
to double up as a router. It can support routing protocols, inspect incoming packets, and can even make routing
decisions based on the source and destination addresses. This is how a layer 3 switch acts as both a switch and a
router.
Often referred to as a multilayer switch, a layer 3 switch adds a ton of flexibility to a network.

Features of a layer 3 switch

The features of a layer 3 switch are:
 Comes with 24 Ethernet ports, but no WAN interface.
 Acts as a switch to connect devices within the same subnet.
 Switching algorithm is simple and is the same for most routed protocols.
 Performs on two OSI layers — layer 2 and layer 3.

Repeaters
Repeaters are network devices operating at physical layer of the OSI model that amplify or regenerate an incoming signal
before retransmitting it. They are incorporated in networks to expand its coverage area. They are also known as signal
boosters.

When an electrical signal is transmitted via a channel, it gets attenuated depending upon the nature of the channel or the
technology. This poses a limitation upon the length of the LAN or coverage area of cellular networks. This problem is alleviated
by installing repeaters at certain intervals.
Repeaters amplifies the attenuated signal and then retransmits it. Digital repeaters can even reconstruct signals distorted by
transmission loss.So, repeaters are popularly incorporated to connect between two LANs thus forming a large single LAN.

Advantages of Repeaters
 Repeaters are simple to install and can easily extend the length or the coverage area of networks.
 They are cost effective.
 Repeaters don’t require any processing overhead. The only time they need to be investigated is in case of
degradation of performance.
 They can connect signals using different types of cables.
GATEWAY
It is a state of a network that can get to different networks. Typically, in the intranet, a node or router can go about as a
router or the gateway node that interfaces the networks are called gateways. In big companies, the PCs that deal with
the traffic between enterprise networks are named gateway nodes. For example, the PCs utilized by Internet service
providers to connect fluctuated users at the moment time to the web are gateway nodes.
It very well may be connected to the router since a router precisely thinks about the routing path of data packets that
shows up at the gateway, then a switch chooses in the reasonable in and out the way of the gateway for the assigned
packet. The gateway is a required trait of courses even though different devices can act well as a gateway.

Hubs
A hub is a physical layer networking device which is used to connect multiple devices in a network. They are
generally used to connect computers in a LAN.
A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these
ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is
destined for a particular destination or not.
 Experiment - 4
Networking Command
IPConfig:
The results of IPConfig include the following information:
Physical Address This is the MAC address for the specified network connection.  A computer can have more than one Physical
address if it has both Ethernet and wireless connections.
Host Name The name of the computer on the network.
IPv4 Address The IP address being used by the network connection.
Subnet Mask The specific section of the network to which a computer is connected.
Default Gateway The router or switch that the network connection goes through.
DHCP Server The server that hands out IP addresses based on a DHCP protocol.
DNS Servers Domain name servers for your network - these servers translate URLs to an IP address.

Ping:
The ping utility has been incorporated into virtually every operating system with network support. While echo request and
echo reply are ICMP messages, the exact implementation of the Ping utility varies slightly among manufacturers.

In its simplest form, the ping utility can be run with nothing more than the ping command and a destination. The remote host
can be specified either by name or address.
Tracert:
The traceroute command attempts to trace the route an IP packet follows to an Internet host by launching UDP probe packets
with a small maximum time-to-live (Max_ttl variable), then listening for an ICMP TIME_EXCEEDED response from
gateways along the way. Probes are started with a Max_ttl value of one hop, which is increased one hop at a time until an
ICMP PORT_UNREACHABLE message is returned. The ICMP PORT_UNREACHABLE message indicates either that the
host has been located or the command has reached the maximum number of hops allowed for the trace.

Item Description

!H Host unreachable

!N Network unreachable

!P Protocol unreachable

!S Source route failed

!F Fragmentation needed

Netstat:
The netstat command symbolically displays the contents of
various network-related data structures for active connections.
The Interval parameter, which is specified in seconds,
continuously displays information regarding packet traffic on
the configured network interfaces. The Interval parameter
takes no flags.
Displays active TCP connections, ports on which the
computer is listening, Ethernet statistics, the IP routing table,
IPv4 statistics (for the IP, ICMP, TCP, and UDP protocols),
and IPv6 statistics (for the IPv6, ICMPv6, TCP over IPv6,
and UDP over IPv6 protocols). Used without parameters, this
command displays active TCP connections.
Nslookup:
Displays information that you can use to diagnose Domain Name
System (DNS) infrastructure. Before using this tool, you should be
familiar with how DNS works. The nslookup command-line tool is
available only if you have installed the TCP/IP protocol.
The nslookup command-line tool has two modes: interactive and
noninteractive.
If you need to look up only a single piece of data, we recommend using
the non-interactive mode. For the first parameter, type the name or IP
address of the computer that you want to look up. For the second
parameter, type the name or IP address of a DNS name server. If you
omit the second argument, nslookup uses the default DNS name server.

Route:
The route command allows you to make manual entries
into the network routing tables. The route command
distinguishes between routes to hosts and routes to
networks by interpreting the network address of
the Destination variable, which can be specified either by
symbolic name or numeric address. The route command
resolves all symbolic names into addresses, using either
the /etc/hosts file or the network name server.

Hostname:
A hostname command is used to view a computer’s
hostname and domain name (DNS) (Domain Name
Service), and to display or set a computer’s hostname or
domain name.
A hostname is a name that is given to a computer that
attached to the network that uniquely identifies over a
network and thus allows it to be accessed without using its
IP address.

ARP:
Displays and modifies entries in the Address
Resolution Protocol (ARP) cache. The ARP cache
contains one or more tables that are used to store
IP addresses and their resolved Ethernet or Token
Ring physical addresses. There is a separate table
for each Ethernet or Token Ring network adapter
installed on your computer. Used without
parameters, arp displays help information.
 Experiment – 5
Installation of Cisco packet tracer and analysis of various tools,
functioning, devices in logical platform, basic pc interconnection,
creation of LAN segment.
Installation Steps:
On the next screen, select “I accept the agreement” and click on “Next”.

Setup will show the folder in which the program’s shortcuts will be created. If you want to change the
folder, you can change it. Click on “Next”.
Then the program will ask whether to create a Desktop icon and create a Quick Launch icon. Make your
choice and click on “Next”.
The summary of the settings we selected is displayed. Click on “Install”.

Cisco packet tracer Installation gets completed. Click “OK” on next popup asking you to close or restart your
computer.
The components of the Packet Tracer interface are as follows:

 Menu bar – this is a common menu found in all software applications; it is used to open, save,
print, change preferences, and so on.
 Main toolbar – this bar provides shortcut icons to menu options that are commonly accessed, such
as open, save, zoom, undo, and redo, and on the right-hand side is an icon for entering network
information for the current network.
 Logical/physical workspace tabs – these tabs allow you to toggle between
the logical and physical work areas.
 Workspace – this is the area where topologies are created and simulations are displayed.
 Common tools bar – this toolbar provides controls for manipulating topologies, such as select,
move layout, place note, delete, inspect, resize shape, and add simple/complex pdu.
 Realtime/simulation tabs – these tabs are used to toggle between the real and simulation modes.
Buttons are also provided to control the time, and to capture the packets.
 Network component box – this component contains all of the network and end devices available
with packet tracer, and is further divided into two areas:
 Device-type selection box – this area contains device categories
 Device-specific selection box – when a device category is selected, this selection box displays the
different device models within that category
 User-created packet box – users can create highly-customized packets to test their topology from
this area, and the results are displayed as a list.
 Experiment -6
Bus Topology

Output :
 Star Topology

Output :
 Ring Topology

Output :
 Tree Topology

Output :
 Mesh Topology

Output :
 Experiment - 7
Simulation of DHCP, difference between static and dynamic IP
assignment.
What is DHCP?

The Dynamic Host Configuration Protocol is a network management protocol used on Internet Protocol
networks for automatically assigning IP addresses and other communication parameters to devices
connected to the network using a client–server architecture.

1. Create the network topology in CISCO packet tracer.

2. Add a server to the network and Configure static IP address on the server.
3. Now configure DHCP service on the server.
Click on the server, then click on Services Tab. Pick DHCP on the menu. Then define the DHCP
network parameters as follows:

Click on add then Save. The DHCP entry is included in the list. Then turn ON the DHCP service.
4. Finally, enable DHCP configuration on each device. They should get automatically configured.
 Experiment - 8
Subnetting
1) Select 2 Switch (PT-Switch) and 2 Router (PT-Empty) from Network Devices (Switch0, Switch1,
Roter1, Router2) and Select 92PC from End Devices (PC0, PC1)
2)Use Copper Cross-over cable to connect same type of device (i.e. Switches) and Copper Straight-
Through cable to connect different types of device (i.e. Switch-PC and Switch-Laptop)
Use FastEthernet port to connect each device as shown below(2 separated subnet)

3) Configure PC :-
Now Assign IP address , Subnet mask and defult gatway to both PCs and Laptops by clicking on device
then go to IP Configuration option of Desktop window.
Assign IP 192.168.1.33,Subnet mask 255.255.255.244 and default gatway 192.168.1.34 to PC0(shown
below) and IP 192.168.1.97,Subnet mask 255.255.255.244 and default gatway 192.168.1.98 to PC1

Configure Router:-
Through interface :Click on router2 select config option and set IP Address 192.168.1.34 and Subnet
Mask 255.255.255.224 to FastEthernet0/0 and select check on Port status box .
 Experiment-9
Establishing a Vlan Network
A VLAN (virtual LAN) is a subnetwork which can group together collections of devices on separate
physical local area networks (LANs). A LAN is a group of computers and devices that share a
communications line or wireless link to a server within the same geographical area.

VLAN, need and advantages:

In essence, a VLAN is a collection of devices or network nodes that communicate with one another as if
they made up a single LAN, when in reality they exist in one or several LAN segments. In a technical
sense, a segment is separated from the rest of the LAN by a bridge, router, or switch, and is typically
used for a particular department. This means that when a workstation broadcasts packets, they reach all
other workstations on the VLAN but none outside it.
VLANs reduce the incidence of collisions and decrease the number of network resources wasted by
acting as LAN segments. Data packets sent from a workstation in a segment are transferred by a bridge
or switch, which will not forward collisions but will send on broadcasts to every network devices. For
this reason, segments are called “collision domains” because they contain collisions within the bounds
of that section.
ADVANTAGES of a VLAN:
They are cost effective.
They offer more flexibility than nonvirtual networking solutions.
 Experiment – 10
Establishing a Inter-VLAN

1) Select a switch and 4 end devices. Connect the switch with end devices through fast ethernet port
cables.

2) Configure the vlans and give them names as marketing and sales.

3) Assign IP addresses to the pc’s as 192.168.1.1, 192.168.1.2 and 192.168.2.1, 192.168.2.2 and ping
them with each other.
4) Establish a simple VLAN network by giving commands on CLI.

5) Now select a router and connect it to the switch with the help of cables, one for vlan 10(fa0/0) and
other for vlan 20(fa0/1).
6) Now open the router CLI and assign the gateways to the pc’s and configure the router by giving ports
and ip addresses.
7) Now to view t hip of router use command show ip route.

8) Enable the switch and write configurations there and use the command spanning tree portfast and
write the ports.

9) Ping the pc’s and Inter vlan routing is hence, established.