11.1 Virtual LANS

Question 1

What is a VLAN

Answer 1

a broadcast domain defined by switch port rather than network address or other criteria. Using VLANs lets you assign devices on different switch ports to different logical (or virtual) LANs.

Question 2

What are the advantages of VLAN

Answer 2

Create virtual LANs based on criteria other than physical location (such as workgroup, protocol, or service).
Simplify device moves by modifying a device’s port assignment to move it to a new VLAN.
Control broadcast traffic and create collision domains based on logical criteria.
Control security by isolating traffic within a VLAN.
Load-balance network traffic by dividing traffic logically rather than physically.

Question 3

VLAN Disadvantages

Answer 3

A disadvantage of using switches to create VLANs is that you might be tied to a specific vendor. Details of how VLANs are created and identified can vary from vendor to vendor. Creating a VLAN might mean you must use only that vendor’s switches throughout the network. When using multiple vendors in a switched network, be sure each switch supports the 802.1Q standards if you want to implement VLANs.

Question 4

Voice VLAN

Answer 4

you can also use switches to create voice VLANs. Voice VLANs are configured on access ports and are used to carry VoIP traffic from a Cisco IP phone. Voice VLANs send all VoIP traffic with a higher priority than data traffic to ensure timely delivery.

Question 5

switch(config)#vlan [1-1005]

Answer 5

Defines a VLAN.

Question 6

switch(config-vlan)#name [unique_name]

Answer 6

Gives the VLAN a name.

Question 7

switch(config)#no vlan [1-1005]

Answer 7

Deletes a VLAN.

Question 8

switch(config-if)#switchport access vlan [1-1005]

Answer 8

Assigns ports to the VLAN.

Question 9

switch#show vlan

switch#show vlan brief

Answer 9

Shows a list of VLANs on the system.

Question 10

switch#show vlan id [1-1005]

Answer 10

switch#show vlan id [1-1005]

Question 11

switch(config-if)#switchport voice vlan [1-1005]

Answer 11

Configures the port to use the specified VLAN for VoIP traffic.

Question 12

switch(config-if)#switchport priority extend cos [0-7]

switch(config-if)#switchport priority extend trust

Answer 12

Sets the priority value that voice traffic will be tagged with. The default is 5.
Configures the port to trust the priority value assigned by the IP phone.

Question 13

switch#sh int [interface] switchport

Answer 13

Displays the configuration information for the specified interface.

Question 14

What is trunking

Answer 14

a term used to describe the connection of two switches