Post on 18-Jan-2016
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NETWORKING DEVICES
Chapter 3
OBJECTIVES Upon completion of this chapter, you
should be able to:Select and install network cards to meet
network connection requirementsConnect a media converterSelect and install appropriate
networking hardwareSelect the appropriate device to connect
two networksIdentify networking and internetworking
devices by name or sight (adapters, hubs, bridges, routers, switches)
NETWORK ADAPTERS
3.1
NETWORK INTERFACE CARDS How do you connect to a wired network?
NIC How do you connect to a wireless
network?WLAN NIC
Both connect devices to the network
MODEM Converts digital to
analog/analog to digitalModulate/demodulate
Connects you to the Internet through the ISP
Cable modem, DSL modem, Dial-up modem
MODULES SFP
Used on routers & switches to convert media type
GBICLarger sized
MEDIA CONVERTERS Layer 1 device Converts signal type
Ethernet to fiber, for example
MAC ADDRESSES Used to identify frame Each host has a unique address
Burned into NIC hardware 48-bits / 12 hex digits / 6 bytes 1st 24 bits OUI; 2nd 24 bits serial #
FORWARDING FRAMES
HOW MAC ADDRESSES ARE SHOWN Written as 0x
0xA4
UNICAST MAC ADDRESS One to one communication
BROADCAST MAC ADDRESS One to all in a network Dest. MAC address will be all F’s DHCP & ARP use broadcasts
MULTICAST MAC ADDRESS One to a group in a network Remote gaming or video conference Dest. IP will be 224.0.0.0 -
239.255.255.255 Dest. MAC will begin with 01-00-5E
REVIEW- 5Q How many bits in a MAC address?
48 bits How many hex digits?
12 The first 6 hex digits are what?
The OUI The OUI would then be the 1st ____ bytes.
3 What important addresses are
encapsulated into a frame?Source & destination MAC
REVIEW- 2Q What kind of message gets sent from
one PC to a group within a network?Multicast
Identify each as unicast, multicast, or broadcast:
ARP Works within your network
LAYER 3
SOURCE IP:192.168.1.1
DESTINATION IP:192.168.1.2
DATA
LAYER 2
SOURCE MAC:AAA
DEST. MAC:
SOURCE IP:192.168.1.1
DEST. IP:192.168.1.2
DATA
HOW ARP WORKS Each device has an ARP table of IP/MACs
Added from communicationAdded from ARP requests
Without a dest. MAC, an ARP request is sent
ARP request is all F’s in what field?Destination MAC
How is an ARP request sent?Broadcast
Who replies to the ARP request?Only one with matching dest. IP
ARP REQUEST & REPLY
HOW ARP WORKS- LOCAL
VIEWING THE ARP TABLE Windows
Arp –a
ACTIVITY TestOut
3.1.3- Select & Install a Network Adapter3.1.4- Connect a Media Converter3.1.5- Quiz
LabsHandout- Fill out MAC address Chart
NETWORK DEVICES
3.2
HUBS Simple Layer 1 device Extends network Data goes in one port & out
all othersNo thinking involvedRelies on devices to decide
on message Creates more network
traffic Not used anymore
HUB NETWORK
BRIDGE Separates segments Layer 2 device Looks at dest. MAC to decide if data
should cross or not Less traffic
WIRELESS BRIDGE Converts wired to wireless
SWITCH Layer 2 device Reads dest. MAC Data enters a port, then
sent out the one port Smarter than bridgeKnows MAC address
on each port MAC Address Table
MAC addresses added Packaged into a FRAME Sent to exact port
HOW A SWITCH WORKS
BUILDING A SWITCH TABLE
WHAT WILL HAPPEN?
REVIEW- 5Q This basic device extends the network, as it
does not segment it. Hub
Which current networking devices receives data and sends it out a single port based on MAC addresses? Switch
What layer does a hub work at? Layer 1
What layer does a switch work at? Layer 2
A switch builds & maintains what? MAC address table
WIRELESS ACCESS POINT (WAP) Allows wireless
devices to connect to wired network Uses radio waves
Like a hub as signal goes to all; dest. MAC accepts
Like a bridge to connect to wired network
WAP reads MAC if you use MAC Filtering
ACTIVITY TestOut
3.2.3- Install a Hub3.2.4- Select a Networking Device3.2.5- Quiz
Interactive Activity (together)
Packet Tracer LabView MAC address tables
Draw network from MAC address table
INTERNETWORK DEVICES
3.3
CONNECTING NETWORKS Each network has a unique set of IP
addresses
To connect different networks, you need a routerWhat layer do routers work at?
3- Network Layer
What addresses do routers read?
ROUTERS Connects different
networks
Reads destination IP addressesDirects packets to
networksDoesn’t care about
specific PC’s
ROUTERS Have one or more network interfaces
Has a table of networks & which interfaces for data to go out to get to those networksRouting table
Usually at the end of your networkBut can be found throughout the inside of
your network
SAMPLE NETWORK 1
SAMPLE NETWORK 2
FIREWALLS Protect network from unauthorized
accessDecides what can enter/leave networkCan check packets for source/dest. address
Hardware FirewallA device or integrated in a routerPlaced between your network & Internet
Still use PC firewall for extra security
LAYER 3 SWITCH Combines functions of a switch & router
Switch that also looks at the destination IP
COMMUNICATE WITHINYOUR NETWORK
COMMUNICATE WITHINYOUR NETWORK- ARP REQUEST
To find the MAC address of a device within your network…ARP request sent as a broadcast
DOES NOT GO OUTSIDE A NETWORK Includes the IP of the destinationEvery NIC looks at it; only one with that IP
will respond with its MAC address
COMMUNICATE OUTSIDE OF YOUR NETWORK If destination IP is outside of network, it
gets sent to the default gateway addressRouter port to get out of the network
PC 1192.168.1.110AA-AA-AA-AA-AA-AA
PC 2192.168.1.111BB-BB-BB-BB-BB-BB
FTP Server192.168.1.9CC-CC-CC-CC-CC-CC
R1192.168.1.111-11-11-11-11-11
R2172.16.1.9922-22-22-22-22-22
Web Server172.16.1.99AB-CD-EF-12-34-56
MAC & IP- TO OTHER NETWORKS Destination IP NEVER changes! Source & Destination MAC changes at
each router interface
COMMUNICATE OUTSIDE YOUR NETWORK- PROXY ARP You don’t know the destination MAC
ARP can’t be sent outside of the network The DG’s MAC address is substituted
ACTIVITY TestOut
3.3.3 Select a Router Lab3.3.4 Quiz
REVIEW- 4Q What addresses do you need to
communicate?Source & Destination IP and MAC
What specific addresses do routers read?Destination IP
To communicate outside of your network, each PC needs this address configured.Default gateway
What is the default gateway?Router port you connect to (way out of your
network)
REVIEW- 3Q When communicating within your
network segment, how does a device find the destination MAC?ARP request
What device inspects packets and protects the network from unauthorized access?Firewall
What device combines layer 2 & 3 functionality?Layer 3 switch
NETWORKING DEVICES
Chapter 3