To configure VTP on a dual-core switch, set the VTP mode, domain name, password, version, and ensure trunk links are active between switches to propagate VLAN information.

Step 1: Access the Switch

Connect to your switch via console, SSH, or Telnet and enter privileged EXEC mode by typing:

CodeCopyenable

Step 2: Enter Global Configuration Mode

CodeCopyconfigure terminal

Step 3: Configure VTP Domain Name

All switches in the same VTP domain must share the same domain name:

CodeCopyvtp domain <domain_name>

For example:

CodeCopyvtp domain cisco

Step 4: Set VTP Mode

Choose the appropriate mode for each switch:

• Server: Can create, modify, and delete VLANs; propagates changes to clients.
• Client: Receives VLAN information from servers; cannot create VLANs.
• Transparent: Forwards VTP messages but does not participate in VLAN database synchronization.

CodeCopyvtp mode servervtp mode clientvtp mode transparent

The default mode is server.

Step 5: Configure VTP Password (Optional but Recommended)

Set a password to authenticate VTP messages across the domain:

CodeCopyvtp password <password>

Example:

CodeCopyvtp password abc123

Step 6: Specify VTP Version

Ensure all switches use the same VTP version (1, 2, or 3):

CodeCopyvtp version 2

Step 7: Enable Trunking on Inter-Switch Links

VTP messages propagate only over trunk links. Configure trunk ports:

CodeCopyinterface <interface_id>switchport mode trunk

Example:

CodeCopyinterface GigabitEthernet0/1switchport mode trunk

Step 8: Verify VTP Configuration

Check the VTP status and ensure VLANs are synchronized:

CodeCopyshow vtp statusshow vlan brief

These commands display the VTP mode, domain, version, password, and VLAN information.

Step 9: Test VLAN Propagation

Create a VLAN on a VTP server switch:

CodeCopyvlan 10name Sales

Then verify that the VLAN appears on VTP client switches using:

CodeCopyshow vlan brief

Best Practices

• Ensure all switches in the domain have the same VTP version and password.
• Avoid misconfigurations that could propagate VLAN deletions across the network.
• Use VTP transparent mode for switches where local VLAN changes should not affect the domain.
• Always configure trunk links between switches to allow VTP messages to pass. By following these steps, your dual-core switches will share VLAN information efficiently, reducing manual configuration and ensuring consistent VLAN deployment across the network .