What devices are used to segment collision domains?
Bridges and switches
Which device isolates one collision domain from another while still connecting them and selectively allowing frames to passfrom one to the other?
A Bridge
What three things must a switch do that seperates it from being a bridge?
address learning
frame forwarding
layer 2 loop removal.
What refers to the intelligent capability of switches to dynamically learn the source MAC addresses of devices that are connected to its various ports?
Address learning
Where does a switch store its MAC table?
RAM
Which device always sends all frames out all ports except the one it came in on?
a hub
Do Switches segment broadcast domains?
no
What will a switch do with a frame if it does not have an entry in its MAC table for the destination MAC in the frame?
flood the frame except the port for which the frame was received on.
What does a switch do after it floods a frame for an unknown destination address?
after the destination host responds to that first frame, the switch will enter the missing MAC address into its table.
What does a switch do with a frame where the source and destination addresses are on the same port?
The switch does not transmit the frame out any ports and assumes that the frame will reach its intended recipient without help from the switch.
How does a switch handle a broadcast frame?
It floods the frame except the port for which the frame was received.
What kind of switching technology does a switch use?
ASIC (hardware)
What kind of switching technology does a hub use?
Software
Is a switch considered fast or slow in terms of speed?
fast
Is a hub considered fast or slow in terms of speed?
slow
Does a switch have High Port Density or Low Port Density?
High
Does a hub have High Port Density or Low Port Density?
low
What kind of duplex does a switch have?
Full and Half
What kind of duplex does a hub have?
half only
Is a switch VLAN-aware?
Yes
Is a hub VLAN-aware?
no
How many collision domains does a switch have?
1 per port
How many collision domains does a hub have?
1 per port
How many broadcast domains does a switch have?
1 per VLAN
How many broadcast domains does a hub have?
1
How many STP instances does a switch have?
1 per VLAN
How many STP instances does a hub have?
1
What are the three switching modes?
Store and Forward
Cut Through
Fragment Free
What is the basic switching mode that switches and hubs use?
Store and Forward
What is the only switching mode that hubs use?
Store and forward
How does the Store and Forward switching mode treat frames?
The entire frame is buffered (copied into memory)
The Cyclic Redundancy Check (CRC), also knownas the FCS or Frame Check Sequence is run to ensure that the frame is valid and not corrupted.
Which switching mode is the fastest?
Cut Through
How does the Cut Through switching mode handle frames?
The switch analyzes the first six bytes of the destination MAC to make its forwarding decision.
Is CRC used in the Cut Through switching mode?
no
What is the disadvantage in using cut through switching modes?
bad frames will be switched along with the good.
Which switching mode is a switching method that picks a compromise between the reliability of Store and Forward and the speed of Cut Through.
Fragment-Free
How does a switch handle a frame when configured for Fragment free switching mode?
it buffers the first 64 bytes of each frame
updates the source MAC and port if necessary
reads the destination MAC
forwards the frame
In fragment free switching mode, what happens to the frames that are less than 64 bytes?
They are discarded
What are frames called that are less than 64 bytes?
runts
What is a nick name for fragment free switching mode?
runtless
What is the sequence of commands used to configure a switch port to use full duplex?
config terminal
interface fastethernet 0/1
duplex full
speed 100
What is the sequence of commands used to configure a switch port to use half duplex?
config terminal
interface fastethernet 0/1
duplex half
speed 10
What is the sequence of commands used to configure a switch port to use auto duplex?
config terminal
interface fastethernet 0/1
duplex auto
speed auto
What is the default duplex configuration for a switch?
auto
What protocol functions as the Layer-2 loop removal?
Spanning Tree Protocol (STP)
What terminology is used to define two or more switchesthat are interconnected by two or more physical links?
A loop
What 3 problems do Switching loops create?
Broadcaststorms
MAC table instability
Duplicate frames
Who originally developed STP?
Digital Equipment Corporation (DEC)
Author
gbird
ID
190655
Card Set
Basic Catalyst Switch Operations and Configurations