Understanding How Vtp Version 3 Works; Vtp Version 3 Authentication - Cisco WS-C2948G-GE-TX Configuration Manual

Chapter 9 Configuring VTP

Understanding How VTP Version 3 Works

VTP version 3 differs from earlier VTP versions in that it does not directly handle VLANs. VTP version 3 is
a protocol that is only responsible for distributing a list of opaque databases over an administrative domain.
When enabled, VTP version 3 provides the following enhancements to previous VTP versions:
•
•
•
•
•
•
•
These sections describe VTP version 3:
•
•
•
•
•

VTP Version 3 Authentication

VTP version 3 introduces an enhancement to the handling of VTP passwords. VTP version 3 allows the
configuration of a primary server. A VTP version 3 server cannot make any configuration changes in the
domain without first becoming the primary server for the domain. The VTP version 3 authentication
enhancements are as follows:
•
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Support for extended VLANs.
Support for the creation and advertising of private VLANs.
Improved server authentication.
Protection from the "wrong" database accidentally being inserted into a VTP domain.
Interaction with VTP version 1 and VTP version 2.
Ability to be configured on a per-port basis.
Note With software release 8.1(1), all VTP versions can be configured on a per-port basis.
Provides the ability to propagate the VLAN database and other databases. VTP version 3 is a collection
of protocol instances, with each instance handling one database that is associated with a given feature.
VTP version 3 handles the configuration propagation of multiple databases (features) independent of
one another by running multiple instances of the protocol.
Note In software release 8.1(1), the only supported database propagation is for the VLAN
database.
VTP Version 3 Authentication, page 9-13
VTP Version 3 Per-Port Configuration, page 9-14
VTP Version 3 Domains, Modes, and Partitions, page 9-14
VTP Version 3 Modes, page 9-18
VTP Version 3 Databases, page 9-19
If no password is configured or if a password is configured the same way as in VTP version 1 or
VTP version 2 (that is, without using the hidden or secret keywords), the following occurs:
– A switch can become the primary server and configure the domain with no restriction.
– The password appears in the configuration.
This is equivalent to the existing VTP version 1 and VTP version 2 levels of security.
Understanding How VTP Version 3 Works
9-13