Post on 23-Mar-2022
transcript
Institute of Technology,Sligo Dept of Computing
Cisco Semester 4
Chapter 1, version 2.1.3
Review
Overview
Chapter 1 is a review of the following subjects:
1.2 LAN Switching
1.2 Virtual LANs
1.3 LAN Design
1.4 Routing Protocols
1.5 Access Control Lists
and 1.6 IPX Routing
1.1 LAN Switching
1.1.1 Congestion and Bandwidth
As more people utilize a network to share large files, access file servers and connect to the Internet, network congestion occurs. To relieve network congestion, more bandwidth is needed or the available bandwidth must be used more efficiently.
1.1 LAN Switching
1.1.2 Why Segment LANs?
By using segments in a network, less users &
devices are sharing the same bandwidth when
communicating within the segment.
This process of creating smaller collision and
broadcast domains is referred to as
segmentation.
1.1 LAN Switching
1.1.3 Segmentation with LAN Switches
A LAN that uses a switched Ethernet topology
creates a network that behaves like it only has two
nodes - the sending node and the receiving node.
They share the 10Mbps bandwidth between them,
which means that nearly all the bandwidth is
available for the transmission of data.
1.1 LAN Switching
1.1.4 LAN Switching Overview
Switching increases the bandwidth available on
a network by creating dedicated network
segments and connecting those segments in a
virtual network within the switch. This circuit
exists only when two nodes need to
communicate.
1.1 LAN Switching
1.1.5 How a LAN Switch Learns Addresses
Switches learn device addresses by:
Reading the source address of each
packet transmitted
Noting the port where the frame was
heard
1.1 LAN Switching
1.1.6 Symmetric Switching
A symmetric switch provides switched
connections between ports with the same bandwidth, such as all 10 Mbps or all 100 Mbps ports.
1.1 LAN Switching
1.1.7 Asymmetric Switching
An asymmetric LAN switch provides
switched connections between ports of unlike bandwidth, such as a combination of 10 Mbps and 100 Mbps ports.
1.1 LAN Switching
1.1.8 Two Switching Methods
Store and Forward - (entire frame is received)
Cut-through - (destination MAC address is read)
Fast Forward - No error checking
and Fragment Free - Checks for collisions