11.2 Trunking

Question 1

What is a Inter-switch link (ISL)

Answer 1

protocol that maintains VLAN information in Ethernet frames as traffic flows between switches and routers, or switches and switches

Question 2

What is 802.1Q

Answer 2

Is an IEEE standard for trunking and is supported by a wide range of devices.
Supports VLAN numbers 1–4094.

Question 3

Switch(config-if)#switchport mode trunk

Answer 3

Enables unconditional trunking on the interface. The port will not use Dynamic Trunking Protocol (DTP) on the interface.

Question 4

Switch(config-if)#switchport trunk encapsulation dot1q
Switch(config-if)#switchport trunk encapsulation isl
Switch(config-if)#switchport trunk encapsulation negotiate

Answer 4

Sets the trunking protocol or allows the trunking protocol to be negotiated

Question 5

Switch(config-if)#switchport trunk native vlan [vlan_id]

Answer 5

Configures the VLAN that is sending and receiving untagged traffic on the trunk port when the interface is in 802.1Q trunking mode.

Question 6

Switch(config-if)#switchport mode access

Answer 6

Disables trunking configuration on the port. The port is set to the access mode unconditionally and operates as a non-trunking, single VLAN interface that sends and receives un-tagged frames.

Question 7

Switch#show interface trunk

Switch#show interface fa0/1 trunk

Answer 7

Shows interface trunking information with mode, encapsulation, trunking status, and VLAN assignments.

Question 8

Describe (DTP) Dynamic Trunking Protocol

Answer 8

used to automatically create a trunk link between two Cisco switches.

Question 9

Switch(config-if)#switchport trunk allowed vlan all
Switch(config-if)#switchport trunk allowed vlan add [vlan_id]
Switch(config-if)#switchport trunk allowed vlan remove [vlan_id]

Answer 9

Defines which VLANs are allowed to communicate over the trunk.
Removes the VLANs that are not allowed to communicate over the trunk.

Question 10

Switch(config-if)#switchport mode dynamic auto

Answer 10

Enables automatic trunking discovery and configuration. The switch uses DTP to configure trunking.

Question 11

Switch(config-if)#switchport mode dynamic desirable

Answer 11

Enables dynamic trunking configuration. If a switch is connected, it will attempt to use the desired trunking protocol. If a switch is not connected, it will communicate as a normal port.

Question 12

Switch(config-if)#switchport mode access

Answer 12

Disables trunking configuration on the port. The port is set to the access mode unconditionally and operates as a non-trunking, single VLAN interface that sends and receives un-tagged frames.

Question 13

Switch(config-if)#switchport access vlan [number]

Answer 13

Assigns an unused interface to an unused VLAN.

Question 14

Switch#show interface trunk

Switch#show interface fa0/1 trunk

Answer 14

Shows the following trunking information for interfaces:
Mode
Encapsulation
Trunking status
VLAN assignments

Question 15

Describe VLAN Trunking Protocol (VTP)

Answer 15

allows VLAN configuration changes to be automatically propagated out to each switch

Question 16

Describe the Server VTP mode

Answer 16

Server mode is the default VTP mode. A switch in server mode can perform the following actions:
Add, remove, and modify VLANs.
Change VTP configuration settings (e.g., change the VTP version number or enable pruning).
Send advertisement messages to propagate changes in the VTP domain.

Question 17

Describe the Client VTP mode

Answer 17

A switch in client mode is able to send and receive VTP advertisement messages but is unable to add, remove, or modify VLAN configurations.

Question 18

Describe Transparent VTP mode

Answer 18

A switch in transparent mode will not obtain configuration information from VTP. However, it will forward VTP messages it receives.

Question 19

Describe Off VTP mode

Answer 19

A switch in off mode will not participate in VTP and will not forward VTP messages.

Question 20

Switch(config)#vtp domain [name]

Answer 20

Configures the VTP domain. The domain name is case sensitive and must be the same for all switches in order for them to send and receive VTP messages.

Question 21

Switch(config)#vtp password [password]

Answer 21

Configures the password for VTP. The same password must be used for all switches in the VTP domain.

Question 22

Switch(config)#vtp mode {server|client|transparent|off}

Answer 22

Changes the VTP mode of the switch.

Question 23

Switch(config)#vtp version 1|2

Answer 23

Enables/disables VTP pruning. VTP pruning is used to eliminate unnecessary traffic in large networks by forwarding only VLAN broadcast traffic to the necessary VLANs.

Question 24

Switch(config)#vtp pruning

Switch(config)#no vtp pruning

Answer 24

Enables/disables VTP pruning. VTP pruning is used to eliminate unnecessary traffic in large networks by forwarding only VLAN broadcast traffic to the necessary VLANs.

Question 25

Switch#show vtp status

Answer 25

Displays the following status information about VTP:
VTP Version: The highest version the switch is capable of, not the version that the switch is using.
Configuration Revision: The revision number of the VTP database. This number should be the same on all switches in the VTP domain.
VTP Operating Mode: The VTP mode of the switch. Possible values are Server, Client, Transparent, and Off.
VTP Domain Name: The configure domain of the switch. This value should be the same for all switches using VTP.
VTP Pruning Mode: Specifies whether VTP pruning is enabled or disabled.
VTP V2 Mode: Shows the version of VTP being used.
Disabled: V1 is being used.
Enabled: V2 is being used.