LAN Switching Fundamentals

Question 1

A switch is powered up, and the system LED is amber. What does this mean ?

Answer 1

The Switch is malfunctioning

Question 2

When transmitting to a remote destination, what 2 things will happen after the IP of the destination has been determined by a host?

Answer 2

The host will broadcast an ARP request for the default gateway address. Then the default gateway device, such as a router, will respond with its own MAC Address

Question 3

Which Cisco IOS command is used to configure private VLAN edge ports on an interface of a Cisco Catalyst 2950 Switch?

Answer 3

switchport protected

Question 4

True of False: Switching reduces collisions domains?

Answer 4

True - each switch network interface is a single collision domain.

Question 5

What are the DTP Modes?

Answer 5

Trunk: The Switch will establish trunk if the other end port is configured as Trunk, Desirable or Auto
Dynamic Desirable: Switch will establish trunk if the other end port is configured as Trunk, Desirable or Auto
Dynamic Auto:Switch will establish trunk if the other end port is configured as Trunk or Desirable
Nonegotiate: Other end port should also be configured with nonegotiate, or should be a device that does not support DTP
Access: No trunk establishment

Question 6

What are the three responses for port security?

Answer 6

Restrict, protect and shutdown.

Restrict - restrict down to the allowed devices while preventing the addiontional ones from communicating

Protect - same as restrict but also logs the violation.

Shutdown - the port is shutdown for any violation and requires administrative intervention to bring it back into service.

Question 7

After a port security violation that has caused the port to be shutdown, what are the steps to being the port back into service?

Answer 7

1. Remove the reason for the violation from the port.
2. Shutdown the port administratively.
3. Issue the no shutdown command.

Question 8

What does STP stand for?

Answer 8

Spanning Tree Protocol

Question 9

What is the purpose of STP?

Answer 9

Spanning Tree Protocol is designed to detect and prevent switching loops in the network. Which in turn prevents broadcast storms.

Question 10

List and explain the benefits and characteristics of VLANs?

Answer 10

VLANs have the following benefits:
Logical, rather than physical, group of devices
Grouping of devices by function or department
Enhanced network security
Decreased size of Broadcast Domains, with increase number of Broadcast Domains.
VLAN greatly simplify adding, moving and changing host(s) in the network

VLANS have the following Characteristics:
VLANs Logically divide a switch into multiple, independent switches at layer 2
A VLAN can span multiples Switches
Trunks Links can carry traffic for multiples VLANS Between the switches and between the switch and router
VLAN create segmented broadcast domains in switches networks.

Question 11

Describe the VTP Server Mode?

Answer 11

VTP Server Mode

• Switch can create, modify or delete VLANs
• Switches send/forward advertisements
• Switches synchronise VTP information
• VLAN information is saved in the NVRAM

Question 12

Describe the VTP Client Mode?

Answer 12

VTP Client Mode

• Switches Forward Advertisements
• Switches synchronise VTP information
• VLAN information is not saved in the NVRAM

Question 13

Describe the VTP Transparent Mode?

Answer 13

VTP Transparent Mode

• Switch can create, modify or delete VLANs
• Switches Forward Advertisements
• Does not synchronise VTP information
• VLAN information is saved in the NVRAM