Switching And Virtual Lans

Question 1

What does power over ethernet provide?

Answer 1

Provides power to devices that are connected to a switch port but are not in a place that has a power outlet.

Question 2

How to add a new host to a vlan

Answer 2

Verfiy the vlan membership of the port

If the membership is different the host will not be able to reach the needed network services

Question 3

What are the purpose of redundant links?

Answer 3

Helps to prevent a network failure in the event a link stops working.

Question 4

What are three disadvantages of redundant links

Answer 4

• frames can be forwarded through redundant links simultaneously causing loops
• additional overhead -port recieving the same fram multiple times
• thrashes mac table- frames from many links confused mac forwarding table

Question 5

Walk through of frame forwarding

Answer 5

• if new source addr is added to mac table, then frame is forwarded
• if source address is know, forwarding begins
• if new destination, frame is floaded out all ports except source port, and destination port is added to table

Question 6

Three switch functions

Answer 6

Address learning, forwarding/ filtering decisions, loop avoidance

Question 7

VLANs break up _________ domains in layer 2 switched network.

Answer 7

Broadcast domains

Question 8

Switches, by default, only break up __________ domains.

Answer 8

Collision

Question 9

What does trunking provide?

Answer 9

Trunking allows you to send information about many or all VLANs through the same link. Access ports allow info about one VLAN transmitted.

Question 10

You need to power a device such as an access point or ip phone. What protocol can provide power to these devices over an ethernet cable?

Answer 10

Power over ethernet

Question 11

You plug a host into a switch port and the host recieves an ip addr, but the use cant get to the services it needs. What is likely the problem?

Answer 11

The vlan port membership is set wrong

Question 12

If the destination mac address is not in the forwarding table, what will the switch do with the frame?

Answer 12

Fload the frame out all ports except the port it was recieved

Question 13

If a frame is recieved on a switch port and the source mac addrrss is not in the forwarding table, what will the switch do?

Answer 13

It will add the source address to the mac table

Question 14

What is ised at layer 2 to prevent switching loops

Answer 14

Spanning tree protocol

Question 15

You need to implement a sperate network fot contractors and guest working at your office. Which yechnology should you implement?

Answer 15

Seperate vlans

Question 16

If you want to imporve your network performabce vy increasing bandwidth available to host and limiting the size of the boradcast domains. Which of the following will help you achieve this goal?
Managed hubs
Bridges
Switches
Switches configured with VLANs

Answer 16

Switches configured with VLANs

Be creating and implementing vlans in your switched network, you can break up broadcast domains at layer 2. For host on different vlans to communicate you need a layer 3 switch

Question 17

The type of ports that can be found on a switch are? (Choose 2)
Vlan trunk protocol
Access
802.1q
Trunk

Answer 17

Access and trunk

Question 18

Which switching technology reduced the size of broadcast domains?
ISL
802.1q
Vlans
Stp

Answer 18

VLANs

Question 19

Which of the following are IEEE versions of STP?
802.1x
Vlan
802.1d
802.11
802.1w

Answer 19

802. 1d

802. 1w

Question 20

Which of the following are benefits of vlans (3)?
Increases the size of collision domains
Allow logical groupings of users by function
Enhance betwork security
Increase block size of broadcast domains, while decreasing collision domains
Simplify switch administration
Increase number of broadcast domains while decreasing size of broadcast domains

Answer 20

Allow logical groupings of users by function
Enhance betwork security
Increase number of broadcast domains while decreasing size of broadcast domains

Question 21

important commands to know

Answer 21

-show interface trunk
- sh interfaces fastethernet 0/15 switchport
-switchport trunk encapsulation dot1q
Switchport mode trunk
Do sh int trunk
Spanning-tree vlan 2 priority 16384
Spanning-tree vlan 3 root primary
Sh spanning-tree vlan 2 (or summary)