Presented by Serge Kpan
LTEC 4550.020
Network Systems Administration
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Agenda
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What is networking?
Networking devices
Hub
Switch
Router
Bridge
Gateway
Firewall
Wireless Access Point
Making all work together
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What is Networking?
 Most people use the internet nowadays but did you ask
yourself what make it work?
 In the computers world, networking is the connection of
two or more computing devices together to share data and
information. Most networks are built on hardware and
software platform.
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Hub
 A hub (also known as repeater) is device that has more
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than one output port.
Contains multiple of data ports where network nodes are
connected.
Operates at the physical layer of the OSI.
Repeat s signal from a node and broadcast it to all other
connected nodes.
Cost: ranges from $15 and up
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Hub Diagram
In this scenario we have a server that is connected to 3
computers via a hub or a switch. When we sent information
(a data packet, or packet) from the server to computer #1,
through the hub, all three computers (1,2 and 3) will receive
the information.
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Switch
 A device that subdivide a network into smaller
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segments
Operates at the Data link layer of the OSI model.
Has multiport and can make better decisions using
MAC address and better use of bandwidth
Smart device
Cost: $50 and up
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Switch Diagram
This scenario shows a home network diagram using a
broadband modem (either ADSL or Cable) such as Netopia
modem for DSL, and a LAN Switch with a couple of
computers.
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Router
 A multiport connectivity device that direct data between
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nodes on different networks.
Can integrate LANs and WANs running at different speeds
and protocols.
Operates at the Network Layer (Layer 3) of the OSI Model.
For enterprise and home use
Cost: $15 and up
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Router Diagram
In this diagram the modem get the information from the
internet and send it to the router who relays that to the
computers.
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Bridge
 A device that connect to network segments by analyzing
incoming traffic frames and making decision about where
to direct them base on their MAC addresses
 Operates at the Data Link layer (Layer 2) of the OSI Model
 A bridge is protocol independent
 Cost: $15 and Up
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Bridge Diagram
This scenario is an example of network segmentation for
better management and bandwidth usage.
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Gateway
 A combination of networking hardware and software that
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connect two different kind of networks.
Can reside on servers, microcomputers, routers, or
mainframes.
Can redirect LAN traffic when no match found for the IP
address on the routing table.
Operate at multilayer of the OSI model but usually at layer
3
Cost: $15 and up
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Gateway Diagram
In this scenario the machine IP number is the default
gateway to get to the rest of the network or the Internet. It
shows the connection of two different kinds of networks,
example a home network and the Internet.
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Firewall
 Firewalls are dedicated security device that stop
unauthorized access from and to a network from (hackers,
viruses, etc) by blocking the data according to the rules up
in its configuration.
 Operate at Multiple layers of the OSI Model usually the
first three layers
 Cost: from $15 and up
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Firewall Diagram
In this figure, we network computers , laptops and a server
protected behind a firewall running on a network router .The
Firewall is used to provide a first line of defense against data
integrity and attacks, and we use the server provides
additional data protection and stability.
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Wireless AP
 Also known as WAP (Wireless Access Point) is a device that
give the ability to wireless devices to connect to a wired
network through, Wi-Fi, Bluetooth, Infrared (IR) or other
related standards.
 Operates at both physical and Data Link of the OSI Model.
 Cost: $29.99 and up
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Wireless AP Diagram
In this scenario multiple wireless devices connect to the
network via the wireless access point. This connection is
setup for wired and wireless network.
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Putting all together!
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What to retain
 A hub repeats signal and transmit it to all nodes in a
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broadcast domain
A switch is an intelligent device that route frames based on
the Mac address and segment networks
A bridge connect dissimilar networks and is software or
hardware based
A router is and intelligent device that routes packets based
on the IP address across networks
Firewalls (or DMZ) filter traffic from and outside a network
to prevent unauthorized access and required some rules
and configuration.
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THANK YOU FOR YOUR ATTENTION
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