CHAPTER
18-1
Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
78-11380-10
18
Configuring VTP
This chapter describes how to use the VLAN Trunking Protocol (VTP) and t he V LAN databa se for
managing VLANs on your Catalyst 2950 or Catalyst 2955 switch.
Note For complete syntax and usage information for the commands used in this chapter, refer to the command
reference for this release.
The chapter includes these sections:
Understanding VTP, page 18-1
Configuring VTP, page 18-6
Monitoring VTP, page 18-16

Understanding VTP

VTP is a Layer 2 messaging protocol that maintains VLAN configuration c onsistency by managing the
addition, deletion, and renaming of VLANs on a network-wide basis. VTP minimizes misc onfigurations
and configuration inconsistencies that can cause several problems, such as duplicate VLAN names,
incorrect VLAN-type specifications, and security violations.
Before you create VLANs, you must decide whether to use VTP in your network. Using VTP, you can
make configuration changes centrally on one or more switches and have those cha nges a uto ma tica lly
communicated to all the other switches in the network. Without VTP, you cannot send information about
VLANs to other switches. VTP configuration information is saved in the VTP VLAN database.
VTP only learns about normal-range VLANs (VLAN IDs 1 to 100 5). E xte nde d-ra nge VLA Ns (VL AN
IDs greater than 1005) are not supported by VTP or stored in the VTP VLAN database. Extended-ra nge
VLANs are only supported when the enhanced software image (EI) is installed.
This section contains information about these VTP parameters:
The VTP Domain, page 18-2
VTP Modes, page 18-3
VTP Advertisements, page 18-3
VTP Version 2, page 18-4
VTP Pruning, page 18-4