Virtual LAN Trunking Protocol

• VTP is a CISCO proprietary protocol

• used to share the VLAN configurations with multiple switches and to maintain consistency throughout that network.

• Information will be passed only if switches connected with FastEthernet or higher ports.

• VTP allows an administrator to add, delete, and rename VLANs-information that is
then propagated to all other switches in the VTP domain.

• Note: Switches Should be configure with same Domain. Domain are not Case sensitive.

VTP Modes

VTP Mode are of three types :


1.Server Mode

2.Client Mode

3.Transparent Mode

Server Mode

o A Switch configured in Server mode can Add , Modify and Delete VLAN’s
o A Default VTP mode for all switches

Client Mode

o A switch configured in Client mode cannot Add , Modify and Delete its VLAN configurations
o Doesn’t store its VLAN configuration information in the NVRAM. Instead learns it from the server every time it boots up

Transparent Mode


o A switch configured in a Transparent Mode can Add , Modify and Delete VLAN configurations.
o Changes in one transparent switch will not affect any other switch.

VTP Pruning


• Preserves bandwidth by configuring it to reduce the amount of broadcasts, multicasts,
and unicast packets.
• VTP pruning only sends broadcasts to trunk links that truly must have the information.
• Enabling pruning on a VTP server, enables it for the entire domain.
• By default, VLANs 2 through 1005 are pruning-eligible, but VLAN 1 can never prune
because it’s an administrative VLAN.
VTP Configuration
Switch(config)# VTP Domain <Name>

Switch(config)# VTP Password <password>

Switch(config)# VTP Mode <server/client/transparent>

Switch(config)# VTP pruning 
 What is VTP?
VLAN Trunking Protocol (VTP) is a Layer 2 messaging protocol that maintains VLAN
configuration consistency throughout a common administrative domain by managing VLANs’
additions, deletions, and name changes across multiple switches. Without VTP, you would
have to add VLAN information in all switches in your network.
What is a VTP domain?
A VTP domain is one or more interconnected switches that share the same VTP environment.
A switch can be in only one VTP domain, and all VLAN information is propagated to all
switches in the same VTP domain.
What are the three VTP modes?
The three VTP modes are
How often are VTP advertisements flooded throughout the management domain?
VTP advertisements are flooded throughout the management domain every 5 minutes or
whenever a change occurs in VLAN configuration.

What is included in VTP advertisements?
VTP advertisements include the following:
VTP revision number
VLAN names and numbers
Information about switches that have ports assigned to each VLAN

What is one of the most important components of the VTP advertisement?
The revision number is one of the most important components of the VTP advertisement.

Every time a VTP server modifies its VLAN configuration, it increments the configuration number by 1. 
The largest configuration number in the VTP domain contains the most current information. When a client receives a revision number higher than its current number, it updates its VLAN configuration.