Configure VTP Server and Client in Switch

VTP (VLAN Tagging Protocol) is a Cisco proprietary VLAN management protocol. It allows you to manage VLAN dynamically. It works in three modes: Server, Transparent, and Client.

Based on the VTP mode you configure on a switch, it is called a VTP Server switch, VTP transparent switch, and VTP client switch. For example, if you configure VTP Server mode on a switch, the switch is called a VTP server. Or if you configure VTP Client mode on a switch, the switch is called a VTP client switch.

You can add and remove VLANs on VTP server switches. The VTP server switches automatically propagate the VLAN information to all other switches. VTP client switches receive VLAN information from VTP servers. VTP transparent switches only pass VLAN information from VTP servers to VTP clients. They do not incorporate the VLAN information they pass through.

Setting up a Packet Tracer LAB

Create a simple practice lab on Packet Tracer, as shown in the following image.

VTP mode configuration commands

We need the following three commands to configure a VTP mode .

switch(config)# vtp domain VTP_domain_name
switch(config)# vtp mode server|client|transparent
switch(config)# vtp password VTP_password

The first command defines a domain name for the switch. Switches share VTP information only inside the domain. They ignore messages received from other domains.

The second command defines the VTP mode of the switch. Server mode is the default VTP mode.

The third command configures a password for the VTP domain. You need to configure this password on all switches of the domain. Switches use it to authenticate VTP messages.

VTP configuration

We will configure Switch0 and Switch2 as VTP servers, Switch3 and Switch4 as VTP clients, and Switch1 as a transparent switch.

VTP Sever configuration on Switch0

Switch>enable
Switch#configure terminal
Switch(config)#vtp domain cisco
Switch(config)#vtp mode server
Switch(config)#vtp password password123
Switch(config)#

VTP Transparent configuration on Switch1

Switch>enable
Switch#configure terminal
Switch(config)#vtp domain cisco
Switch(config)#vtp mode transparent
Switch(config)#vtp password password123
Switch(config)#

VTP Sever configuration on Switch2

Switch>enable
Switch#configure terminal
Switch(config)#vtp domain cisco
Switch(config)#vtp mode server
Switch(config)#vtp password password123
Switch(config)#

VTP Client configuration on Switch3

Switch>enable
Switch#configure terminal
Switch(config)#vtp domain cisco
Switch(config)#vtp mode client
Switch(config)#vtp password password123
Switch(config)#

VTP Client configuration on Switch4

Switch>enable
Switch#configure terminal
Switch(config)#vtp domain cisco
Switch(config)#vtp mode client
Switch(config)#vtp password password123
Switch(config)#

Trunk configuration

A switch port can work in two modes: access and trunk. In access mode, it works with a single VLAN. In trunk mode, it works with multiple VLANs. Access mode is the default mode on all switch ports. In a multi-VLAN environment, we need to change the default mode to trunk mode on all switch ports that connect switches.

Trunk configuration on Switch0

Switch(config)#interface gigabitethernet 0/1
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#interface gigabitethernet 0/2
Switch(config-if)#switchport mode trunk
Switch(config-if)#

Trunk configuration on Switch1

Switch(config)#interface gigabitethernet 0/1
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#interface gigabitethernet 0/2
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#

Trunk configuration on Switch2

Switch(config)#interface gigabitethernet 0/1
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#interface gigabitethernet 0/2
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#

Trunk configuration on Switch3

Switch(config)#interface gigabitethernet 0/2
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit
Switch(config)#

Trunk configuration on Switch4

Switch(config)#interface gigabitethernet 0/1
Switch(config-if)#switchport mode trunk
Switch(config-if)#exit

VLAN configuration

We use the vlan command to create VLANs. We need to create VLANs only on the VTP server. Other switches will automatically receive VLAN information from the VTP server.

In this network, we have two VTP servers. Create two VLANs on Switch0.

Switch(config)#vlan 10
Switch(config-vlan)#exit
Switch(config)#vlan 20
Switch(config-vlan)#exit
Switch(config)#

To view VLAN information, we use the show vlan command in privileged exec mode. Run this command on Switch0 to verify the VLAN configuration.

Switch0 is a VTP Server. It will automatically propagate VLAN information to VTP clients. To verify this, you can check the VLAN configuration on VTP clients.

We configured Switch3 and Switch4 as VLAN clients.

Updating VLAN information

You can update VLAN information on any VTP server in the VTP domain. In this network, we have two VTP servers: Switch0 and Switch2. We created VLANs on the Switch0. Let us use Switch2 to update the VLAN information.

Switch(config)#vlan 30
Switch(config-vlan)#exit

View VLAN information on Switch3 or Switch4 again to verify the update.

Verifying VTP transparent mode

In transparent mode, switches only pass VLAN information from VTP servers to VTP clients. They do not incorporate the VLAN information they pass through.

To verify this, you can check the VLAN information on Switch1.

Let us add one VLAN on Switch1.

Switch(config)#vlan 40
Switch(config-vlan)#exit

View the VLAN information again to verify the new VLAN.

Since we created this VLAN on a transparent switch, it will not propagate it to other switches. To verify this, you can view VLAN information on Switch3 or Switch4 again.

Viewing VTP password

The show vtp password command displays the configured vtp password on the switch.

Viewing VTP statistics

The show vtp counters command displays the VTP statistics.

Viewing VTP status

The show vtp status command displays the VTP status.

That's all for this tutorial. In this tutorial, we learned how to configure, test, and verify VTP modes.