Cisco ICND1 Quiz: Switched LAN Topology

Collision Domain
The set of LAN interfaces (say NIC) whose frames would collide with each other, but  not with frames sent by an other devices in the network.
- On a Switch one switchport one collision domainÉ. Switchports connected to one device is dedicated bandwidth, and can support full duplex and rate adaptation. Different Ethernet speeds can communicate through a switch not a hub.

Bridges and Routers also separate LANs into different collision domains.
Compare this with a Hub or repeater; does not create multiple collision domains for each interface, it just repeats all frames out all ports.

In a single collision domain the devices share the available bandwidth

Broadcast Domain
The terms refers to where broadcasts can be forwarded. The domain within where one devices sends a broadcast and the others receive a copy. A switch floods broadcast and multicast out all ports. A single switch creates a single broadcast domain.

A router stops the flow of broadcasts.
But an IP ARP  is a LAN Broadcast

Scenarios
Consider a LAN with multiple switches with 500 PC.  The switces are part of the same broadcast domain, so imagine one broadcast sent by one PC is processed by 499 others! A better idea would be to separate 500 machines into five groups of 100, segmented by a router. Then one broadcast from one host would only impact 99 others.
The answers are tricky!

Feature                                                  Hub     Switch     Router
Greater cabling distances are allowed  Y         Y              Y
Creates multiple collision domains       N        Y              Y
Increases bandwidth                              N        Y              Y   
Creates multiple broadcast domains     N         N              Y
You could do VLANs, to segment the device into smaller LANs (broadcast domains) to reduce overhead

Topology
Access switches - connect to end users, like multiple PC hosts.
Distribution switches - provids a path to the core switch. One access switch would have atleast two uplinks to distribution switches for redundancy
Core switches - higher forwarding rates, more aggregation benefits for very large campus LANs.
1. What are characteristics of a bridge? choose three
a) Bridges forward but do not filter data frames between LAN segments
b) Bridges maintain MAC address tables
c) Bridges are more intelligent than hubs
d) Bridges can buffer and forward frames between two or more LAN segments
e) Bridges create fewer collision domains
f) Bridges operate at Layer 3 or the OSI model

2 .Which three characteristics apply to a switch? choose three
a) uses a table of MAC addresses to determine the port to which the data is to be sent
b) connects LAN segments
c) reduces the number of collision domains
d) increases the number of collision domains
e) filters data before forwarding it to the its destination on the network

3. Which three features differentiate switches from bridges? choose three
a) large frame buffers
b) use of a table of MAC addresses to determine the segment to whicih the data is to be sent
c) support for the mixed media rates
d) high port densities
e) ability to segment LANs

4. Which is not provided by flow control
a. Windowing
b. Buffering
c. full duplex transmission
d. source quench messaging

1. bcd
2. abd
3. acd
4. c (explanation: an Ethernet concept)