Cisco VTP VLAN Trunking Protocol

(VTP) is a Cisco Layer 2 messaging protocol that manages the addition, deletion, as well as renaming of VLANs on a network-wide basis. Virtual Local Area Network (VLAN) Trunk Protocol (VTP) reduces direction inwards a switched network. When you lot configure a novel VLAN on i VTP server, the VLAN is distributed through all switches inwards the domain. This reduces the demand to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on close of the Cisco Catalyst Family products. VTP ensures that all switches inwards the VTP domain are aware of all VLANs. There are occasions, however, when VTP tin exercise unnecessary traffic. All unknown unicasts as well as broadcasts inwards a VLAN are flooded over the entire VLAN. All switches inwards the network have all broadcasts, fifty-fifty inwards situations where few users are connected inwards that VLAN. VTP pruning is a characteristic used to eliminate (or prune) this unnecessary traffic. By default, all Cisco Catalyst switches are configured to endure VTP servers. This is suitable for small-scale networks where the size of the VLAN information is minor as well as easily stored inwards all switches (in NVRAM). In a large network, a judgment telephone telephone must endure made at unopen to indicate when the NVRAM storage needed is wasted, because it is duplicated on every switch. At this point, the network administrator should conduct a few well-equipped switches as well as perish along them equally VTP servers. Everything else participating inwards VTP tin endure turned into a client. The number of VTP servers should endure chosen therefore equally to render the flat of redundancy desired inwards the network.

Modes of OperationServer

In VTP server mode, you lot tin create, modify, as well as delete VLANs as well as specify other configuration parameters (such equally VTP version as well as VTP pruning) for the entire VTP domain. VTP servers advertise their VLAN configuration to other switches inwards the same VTP domain as well as synchronize their VLAN configuration alongside other switches based on advertisements received over torso links. VTP server is the default mode.

Transparent

VTP transparent switches exercise non participate inwards VTP. Influenza A virus subtype H5N1 VTP transparent switch does non advertise its VLAN configuration as well as does non synchronize its VLAN configuration based on received advertisements. However, inwards VTP version 2, transparent switches exercise forwards VTP advertisements that they have out their torso ports.

Client

VTP clients deport the same agency equally VTP servers, but you lot cannot create, change, or delete VLANs on a VTP client.

Advertisements Summary Advertisements

When the switch receives a summary promotion packet, it compares the VTP domainname to its ain VTP domain name. If the yell is different, the switch but ignores the packet. If the yell is the same, the switch as well as then compares the configuration revision to its ain revision. If its ain configuration revision is higher or equal, the parcel is ignored. If it is lower, an promotion asking is sent.

Subset Advertisements

When you lot add, delete, or modify a VLAN inwards a switch, the server switch where the changes were made increments the configuration revision as well as issues a summary advertisement, followed yesteryear i or several subset advertisements. Influenza A virus subtype H5N1 subset promotion contains a listing of VLAN information. If at that topographic point are several VLANS, to a greater extent than than i subset promotion may endure required inwards social club to advertise them all.

Advertisement Requests

Influenza A virus subtype H5N1 switch needs a VTP promotion asking inwards the next situations:

The switch has been reset. The VTP domain yell has been changed. The switch has received a VTP summary promotion alongside a higher configuration revision than its own. Upon receipt of an promotion request, a VTP device sends a summary advertisement, followed yesteryear i or to a greater extent than subset advertisements.

Configuration To configure an IOS based switch to endure a VTP server, upshot the next commands:

SwitchA# vlan database

SwitchA(vlan)# vtp domain CiscoKits

SwitchA(vlan)# vtp server

SwitchA(vlan)# exit

These commands configure the switch to endure a VTP server inwards the VTP domain CiscoKits. The changes are saved as well as the revision number is incremented when the larn out ascendence is issued. To configure a VTP client, run the next commands:

SwitchB# vlan database

SwitchB(vlan)# vtp domain CiscoKits

SwitchB(vlan)# vtp customer

SwitchB(vlan)# exit

To disable VTP, ready the vtp trend to transparent equally such:

SwitchC# vlan database

SwitchC(vlan)# vtp transparent

SwitchC(vlan)# exit

To monitor the VTP performance as well as status, purpose either:

SwitchA# demo vtp status

or

SwitchA# demo vtp counters.