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This work is licensed with a
Creative Commons Attribution 4.0 International LicenseEndFragment
This material was developed with funding
from the National Science Foundation
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Network Devices
Encryption
SSID
Introduction
Authentication
TKIP
CCMP
Data Integrity
Key Management
Replay
Network devices (or network hardware) are physical devices that are required for communication and interaction between hardware on a computer network. The network device connects various other devices (computers, tablets, smartphones, laptops, or printers) together to transfer data or files.
WEP
Key Management
WPA
Data Integrity
Capability-based AI
Repeater
Transceiver
Router
Hub
Bridge
Switch
Modem
Access Point
A transceiver gets its name from being both a transmitter and a receiver of both analog and digital signals. The transceiver places signals onto the network media and detects incoming signals traveling through that same cable.
Often other network devices such as a router or switch will need a transceiver to connect a fiber optic cable to the device.
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A modem is a device that either modulates or demodulates a signal. The modem connects customers to the cable company through a cable connector (copper, fiber, or wireless). The modem converts signals received into signals that a local device can use (and vice versa). Typically, a modem converts an analog signal received to a digital signal on your home network or office. Modems also convert a digital signal like a fiber signal from the cable company to a different form of digital signal used in your home. Modems can be integrated into a wireless router.
1
A network repeater re-times and regenerates a signal to extend the distance over which data can safely transmit. It compensates for signal attenuation. Attenuation is the loss of signal strength in network cables or connections. Network repeaters are often used to extend a signal over a long distance. Repeaters can be used on copper, fiber and wireless networks.
Weakened Signal
Regenerated Signal
Workstations listen for the packet and identify the destination MAC address. Only the destination workstation receives the packet.
click packet
to continue
A hub is a multiport repeater. Instead of just regenerating the signal out one port, it sends the signal to all ports on the hub. Devices connected to a hub must listen for traffic being transmitted. If the network is busy, the device will wait a random period of time and check back. If the network is still busy, it will wait again until it does not sense traffic. The device can then transmit. Sometimes multiple devices will listen and NOT sense traffic. These devices will then transmit. This can cause a collision. If a collision is sensed, all transmitting stations will relisten then transmit when the network is free of traffic. Hubs generate excessive network traffic.
Broadcast Domain B
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MAC Address Table
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EndFragment
MAC Address Table
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EndFragment
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<
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Broadcast Domain A
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The bridge is a physical hardware device, but it operates at the OSI model's data link layer. Bridges connect two different collision domains which are formed by network hubs. Bridges learn the MAC address of each device and record it in a port MAC address table. If a destination address is on the opposite port of the bridge, the packet gets forwarded through the bridge. A bridge prevents a broadcast domain from getting too large.
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DATA
A network switch is a multiport bridge. Unlike a hub, the switch only forwards data packets between the source and destination devices. Like bridges, a switch learns the MAC address of each device connected to the switch. The switches only send each packet directly to the destination device using the MAC address learned as each device connects to a port on the switch.
Source Address
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Ethernet Frame
Destination Address
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MAC Address TablePort 1:
Port 2:
Port 3:
Port 4:
Port 5:
Port 6:
Port 7:
Port 8:
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SSID = RING
Passphrase: 1234567890
An access point is a wireless network device that acts as a portal for devices to connect to a local area network. Access points work like network hubs--they simply act as wireless multi port repeaters. Newer AP's with multiple radios and SSIDs can act like network switches. Access points are used for extending the wireless coverage of an existing network and for increasing the number of users that can connect to it.
Interface 1
This router subdivides the assigned network address into subnets
Network
Destination Network Address
Full Class C = 190.100.1.0 255.255.255.0 Network Address = 190.100.1.0
Address Range 190.100.1.1-254
Broadcast Address = 190.100.1.255
Interface 2
Destination Network Address
Full Class C = 190.100.1.16 255.255.255.240
Network Address = 190.100.1.16
Address Range 190.100.1.17-30
Broadcast Address = 190.100.1.31
Internet
Destination Network Address
Full Class C = 190.100.1.48 255.255.255.240
Network Address = 190.100.1.48
Address Range 190.100.1.49-62
Broadcast Address = 190.100.1.63
Subnet X
The router transmits data packets between local area networks. Routers require an IP address to send data from one network to another. Routers build a routing table using static or dynamic routing protocols to move traffic across the Internet. Subnetting requires routers. The organization’s router has four physical connections called interfaces. Each interface connects to one of the organization’s subnets. Each subnet has an assigned network address, a range of usable IP addresses, and a broadcast address. If users in one of the subnets tries to communicate with a user in a different subnet, the router forwards the traffic to the destination subnet. If a user accesses the Internet, the router forwards and receives that traffic.
Click each
Subnet box
Interface 3
Subnet Y
Interface 0
Destination Network Address
Full Class C = 190.100.1.32
255.255.255.240
Network Address = 190.100.1.32
Address Range 190.100.1.32-46
Broadcast Address = 190.100.1.47
Subnet Z