LAN Switching and Wireless Basic Switch Concepts and Configuration.
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Transcript of LAN Switching and Wireless Basic Switch Concepts and Configuration.
LAN Switching and Wireless Basic Switch Concepts and Configuration
Objectives Summarize the operation of Ethernet as defined for
100/1000 Mbps LANs in the IEEE 802.3 standard.
Explain the functions that enable a switch to forward Ethernet frames in a LAN.
Configure a switch for operation in a network designed to support voice, video, and data transmissions.
Configure basic security on a switch that will operate in a network designed to support voice, video, and data transmissions.
Summarize the operation of Ethernet as defined for 100/1000 Mbps LANs in the IEEE 802.3 standard
Key elements of Ethernet/802.3 networks
Communication types reminder
Unicast – to a single host address e.g. most user traffic: http, ftp, smtp etc.
Broadcast – addressed to all hosts on the network e.g. ARP requests.
Multicast – to a group of devices e.g. routers running EIGRP, group of hosts using videoconferencing. IP addresses have first octet in range 224 – 239.
Summarize the operation of Ethernet as defined for 100/1000 Mbps LANs in the IEEE 802.3 standard
Design considerations for Ethernet/802.3 networks
Network Latency
NIC delay – time taken to put signals on medium from one end and to translate it on the other end.
Propagation delay – time spent travelling on medium
Latency from intermediate devices e.g. switch or router. Depends on number and type of devices. Routers add more latency than switches.
key elements of Ethernet 802.3 networks CSMA/CD (Carrier sense multi access /
Collision detection): it is the IEEE 802.3 standard.
• Carrier Sense
In CSMA/CD, all devices that have messages to send must listen before transmitting.
If a device detects a signal from another device, it waits before attempting to transmit.
When there is no traffic detected the device starts transmitting its message.
While this transmission is occurring, the device continues to listen for traffic on the LAN.
After the message is sent, the device returns to its default listening mode.
• Multi-access
If the signals of one device are not detected by a second device, the second device may also starts to transmit.
The media now has two devices transmitting messages at the same time.
The messages travel across the media and once they meet each other then a collision happens and the messages are destroyed.
Note: CSMA/CD is only used with half-duplex communication typically found in hubs. In full-duplex mode the collision detect circuit is disabled.
key elements of Ethernet 802.3 networks
Collision Detection
When a device is in listening mode, it can detects a collision that might happens in the media.
Jam Signal and Random Back off
When collision is detected, the transmitting devices send out a jamming signal.
The jamming signal notifies other devices of a collision and that they need to back off and stop transmitting for a random amount of time.
Explain the Functions that Enable a Switch to Forward Ethernet Frames in a LAN
Explain the Functions that Enable a Switch to Forward Ethernet Frames in a LAN
Explain the Functions that Enable a Switch to Forward Ethernet Frames in a LAN
Explain the Functions that Enable a Switch to Forward Ethernet Frames in a LAN
Configure a Switch for Operation in a Network
Configure a Switch for Operation in a NetworkCisco IOS help facilities
Configure a Switch for Operation in a Network
Cisco IOS commands to access the command history
Configure a Switch for Operation in a Network
Configure a Switch for Operation in a Network
Prepare the switch to be configured
Configure a Switch for Operation in a Network
The basic switch configuration
console
Ethernet
Configure a Switch for Operation in a Network
Configure a Switch for Operation in a Network
Configure Basic Security on a Switch
Configure Basic Security on a Switch
Configure Basic Security on a Switch
Cisco IOS commands used to disable unused ports
Configure Basic Security on a Switch
Questions
Describe the operation of Ethernet as defined for 100/1000 Mbps LANs in the IEEE 802.3 standard.
What functions enable a switch to forward Ethernet frames in a LAN?
How do you configure a switch for operation in a network designed to support voice, video, and data transmissions?
Summary LAN Design
Process that explains how a LAN is to be implemented
Factors to consider in LAN design include
Collision domains
Broadcast domains
Network latency
LAN segmentation
Summary
Switch forwarding methods
Store & forward – used by Cisco Catalyst switches
Cut through – 2 types
Fast forwarding
Cut through
Summary
Symmetric switching
Switching is conducted between ports that have the same bandwidth
Asymmetric switching
Switching is conducted between ports that have unlike bandwidth
Summary
CISCO IOS CLI includes the following features
Built in help
Command history/options
Switch security
Password protection
Use of SSH for remote access
Port security