To configure a VTP client, run the following commands: The changes are saved and the revision number is incremented when the exit command is issued. These commands configure the switch to be a VTP server in the VTP domain CiscoKits. Upon receipt of an advertisement request, a VTP device sends a summary advertisement, followed by one or more subset advertisements.Ĭonfiguration To configure an IOS based switch to be a VTP server, issue the following commands: The switch has received a VTP summary advertisement with a higher configuration revision than its own. If there are several VLANS, more than one subset advertisement may be required in order to advertise them all.Ī switch needs a VTP advertisement request in the following situations: A subset advertisement contains a list of VLAN information. When you add, delete, or change a VLAN in a switch, the server switch where the changes were made increments the configuration revision and issues a summary advertisement, followed by one or several subset advertisements. If it is lower, an advertisement request is sent. If its own configuration revision is higher or equal, the packet is ignored. If the name is the same, the switch then compares the configuration revision to its own revision. If the name is different, the switch simply ignores the packet. When the switch receives a summary advertisement packet, it compares the VTP domainname to its own VTP domain name. VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client. However, in VTP version 2, transparent switches do forward VTP advertisements that they receive out their trunk ports. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements. VTP transparent switches do not participate in VTP. VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. In VTP server mode, you can create, modify, and delete VLANs and specify other configuration parameters (such as VTP version and VTP pruning) for the entire VTP domain. The number of VTP servers should be chosen so as to provide the degree of redundancy desired in the network. Everything else participating in VTP can be turned into a client. At this point, the network administrator should choose a few well-equipped switches and keep them as VTP servers. In a large network, a judgment call must be made at some point when the NVRAM storage needed is wasted, because it is duplicated on every switch. This is suitable for small-scale networks where the size of the VLAN information is small and easily stored in all switches (in NVRAM). By default, all Cisco Catalyst switches are configured to be VTP servers. VTP pruning is a feature used to eliminate (or prune) this unnecessary traffic. All switches in the network receive all broadcasts, even in situations where few users are connected in that VLAN. All unknown unicasts and broadcasts in a VLAN are flooded over the entire VLAN. There are occasions, however, when VTP can create unnecessary traffic. VTP ensures that all switches in the VTP domain are aware of all VLANs. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Catalyst Family products. This reduces the need to configure the same VLAN everywhere. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. Virtual Local Area Network (VLAN) Trunk Protocol (VTP) reduces administration in a switched network. (VTP) is a Cisco Layer 2 messaging protocol that manages the addition, deletion, and renaming of VLANs on a network-wide basis. CCNA Tutorial: Cisco VTP VLAN Trunking Protocol