VTPv3

Posted: 1st June 2020 by ccna7guru in ITN

VTP version 3 provides some significant benefits to the network administrator:

  • The ability to create a primary server was added. In VTP versions 1 and 2, all VTP server switches are equal; any one of them may add, remove, or rename VLANs and change their state. In VTP version 3, only the primary server can do this. There can be only one primary server present in a VTP domain. The role of a primary server is to be in a runtime state. It is not a part of the configuration; rather, this state is requested in privileged EXEC mode and is relinquished whenever another switch attempts to become the primary server, or when the switch is reloaded.
  • VTP version 3 has the ability to hide the VTP password. On a VTP version 1 or 2 switch, issuing the command show vtp password will show the password to you in plaintext. VTP version 3 allows you to specify that the password be hidden in the output, preventing the password from being inadvertently or maliciously divulged.
  • VTP version 3 can propagate information about extended range VLANs; These are VLANs numbered between 1006 and 4094. To support these VLANs with VTP version 1 or 2, all switches have to be in Transparent or Off mode and the VLANs must be configured manually on a switch-by-switch basis.
  • VTP version 3 only supports pruning for normal-range VLANs.
  • VTP version 3 supports propagating Private VLAN information. As with extended-range VLANs, the lack of PVLAN support in VTP version 2 required that all switches be in Transparent mode and manually configured at each switch.
  • VTP version 3 added support for opaque databases. In other words, VTP version 3 can transport more than just the VLAN database between switches. The only option at this time is to share the Multiple Spanning Tree (MSTP) database, but room was left for expansion.
  • Regardless of the VTP operating mode, a VTP domain must first be set before configuring VTP version 3.
  • VTP version 3 is backwards compatible with VTP version 2 for normal range VLANs only; at the boundary of the two protocols, a VTP version 3 switch will send out both version 3 and version 2-compatible messages. Version 2 messages received by a version 3 switch are discarded.