VTP (Vlan trunking protocol – Cisco )
1. What are different VLAN modes?
VLAN modes refer to how switches handle VLAN (Virtual Local Area
Network) information. The main VLAN modes are:
Access Mode: The interface belongs to a single VLAN and carries
traffic for only one VLAN.
Trunk Mode: The interface can carry traffic for multiple VLANs
by tagging frames with the appropriate VLAN ID.
Dynamic Desirable Mode: The interface actively attempts to
convert the link into a trunk by negotiating with the remote
interface.
Dynamic Auto Mode: The interface will automatically become a
trunk link if the other side actively tries to form a trunk.
2. What happens to interfaces when you delete a VLAN?
When a VLAN is deleted:
The interfaces assigned to the deleted VLAN are not removed but
become inactive.
Those interfaces will no longer pass traffic until they are assigned
to an active VLAN.
Any configuration related to the deleted VLAN, such as port
assignments, is lost.
3.What are VTP modes.
VTP (VLAN Trunking Protocol) operates in different modes, which
define how switches interact within the VTP domain for VLAN
management. The main VTP modes are:
1. VTP Server Mode (Default Mode):
The switch can create, modify, and delete VLANs.
It advertises its VLAN information to other switches in the VTP
domain.
VLAN changes made on a VTP server are propagated to all other
switches in the domain.
It saves VLAN configurations in NVRAM (persistent memory).
2. VTP Client Mode:
The switch cannot create, delete, or modify VLANs.
It listens for updates from VTP servers and synchronizes its VLAN
database with the VTP server's information.
VLAN configurations are not saved in NVRAM; if the switch
reboots, it must receive updates from a server to restore the
VLANs.
The client depends entirely on the VTP server for VLAN
management.
3. VTP Transparent Mode:
The switch does not participate in VTP domain updates,
meaning it does not advertise or synchronize VLAN information.
However, it forwards VTP advertisements it receives to other
switches.
The switch can create, delete, and modify local VLANs, but
these changes are not propagated to other switches in the
domain.
VLANs are stored in the switch's NVRAM.
In short
Server: Full control (can create, modify, delete VLANs, and propagate
them).
Client: Receives and applies VLAN changes from a server (no local
VLAN changes allowed).
Transparent: Local VLAN control without participating in VTP domain-
wide synchronization.
4. What is the difference between VTP Transparent and VTP Client
mode?
VTP Transparent Mode: The switch does not participate in the
VTP process. It will not synchronize its VLAN database with other
switches, but it can create, delete, and modify local VLANs.
Transparent switches forward VTP messages but do not apply
changes.
VTP Client Mode: The switch cannot create, delete, or modify
VLANs locally. It synchronizes its VLAN database with the VTP
server but only when receiving updates. Client switches rely on
the VTP server for VLAN configurations.
5. Which is the default mode of VTP?
The default mode of VTP is Server Mode. In this mode, a switch can
create, modify, and delete VLANs and share this information with
other switches in the VTP domain.
6. What is VTP Pruning?
VTP Pruning is a feature that helps to reduce unnecessary VLAN traffic
on trunk links. It stops VLAN traffic from being sent over a trunk link if
the VLAN is not active or used on the receiving switch, improving
bandwidth efficiency.
7. What are two benefits of using VTP in a switching environment?
1. Centralized VLAN Management: VLANs can be created and
managed centrally from a VTP server, and changes are
automatically propagated to all switches in the VTP domain.
2. Consistent VLAN Configuration: VTP helps maintain consistent
VLAN configuration across the network, reducing errors in VLAN
setup and simplifying network administration.
8. Which VTP mode is capable of creating only local VLANs and does
not synchronize with other switches in the VTP domain?
VTP Transparent Mode allows a switch to create, modify, and delete
only local VLANs and does not synchronize VLAN information with other
switches in the VTP domain.
9. what are requirement of VTP configuration.
VTP Configuration
Switch(config)# vtp mode {server | client | transparent}
Switch(config)# vtp domain <name>
Switch(config)# vtp password <password>
Switch(config)# vtp version {1 | 2}
Switch(config)# vtp pruning
Practical
SW1(config)#vtp domain study-ccna
Changing VTP domain name from NULL to study-ccna
SW1(config)#vtp password cisco
Setting device VLAN database password to cisco
SW2(config)#vtp mode client
Setting device to VTP CLIENT mode.
SW2(config)#vtp domain study-ccna
Changing VTP domain name from NULL to study-ccna
SW2(config)#vtp password cisco
Setting device VLAN database password to cisco
SW3(config)#vtp mode client
Setting device to VTP CLIENT mode.
SW3(config)#vtp domain study-ccna
Changing VTP domain name from NULL to study-ccna
SW3(config)#vtp password cisco
Setting device VLAN database password to cisco
On SW1, we will create a new VLAN:
SW1(config)#vlan 30
SW2 and SW3 will create the VLAN 30 automatically. We can use
the show vlan command on both switches to verify this (in this example
VLAN 2 ‘Accounting’ was also already created on SW1):
To display the VTP configuration information, we can use the show vtp
status command:
