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Catalyst 2960 and 2960-S Switch Software Configuration Guide
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Chapter 14 Configuring VTP
Configuring VTP
• Do not enable VTP version 2 on a switch unless all of the switches in the same VTP domain are
version-2-capable. When you enable version 2 on a switch, all of the version-2-capable switches in
the domain enable version 2. If there is a version 1-only switch, it does not exchange VTP
information with switches that have version 2 enabled.
• We recommend placing VTP version 1 and 2 switches at the edge of the network because they do
not forward VTP version 3 advertisements.
• If there are TrBRF and TrCRF Token Ring networks in your environment, you must enable VTP
version 2 or version 3 for Token Ring VLAN switching to function properly. To run Token Ring and
Token Ring-Net, disable VTP version 2.
• VTP version 1 and version 2 do not propagate configuration information for extended range VLANs
(VLANs 1006 to 4094). You must configure these VLANs manually on each device. VTP version 3
supports extended-range VLANs. You cannot convert from VTP version 3 to VTP version 2 if
extended VLANs are configured.
• When a VTP version 3 device trunk port receives messages from a VTP version 2 device, it sends a
scaled-down version of the VLAN database on that particular trunk in VTP version 2 f ormat. A VTP
version 3 device does not send VTP version 2-formatted packets on a trunk unless it first receives
VTP version 2 packets on that trunk port.
• When a VTP version 3 device detects a VTP version 2 device on a trunk port, it continues to send
VTP version 3 packets, in addition to VTP version 2 packets, to allow both kinds of neighbors to
coexist on the same trunk.
• A VTP version 3 device does not accept configuration information from a VTP version 2 or version
1 device.
• Two VTP version 3 regions can only communicate in transparent mode over a VTP version 1 or
version 2 region.
• Devices that are only VTP version 1 capable cannot interoperate with VTP version 3 devices.

Configuration Requirements

When you configure VTP, you must configure a trunk port on the switch stack so that the switch can send
and receive VTP advertisements to and from other switches in th e domain.
For more information, see the “Configuring VLAN Trunks” section on page 13-13.
If you are configuring VTP on a cluster member switch to a VLAN, use the rcommand privileged EXEC
command to log in to the member switch. For more information about the command, see the command
reference for this release.
In VTP versions 1 and 2, when you configure extended-range VLANs on the switch, the switch must be
in VTP transparent mode. VTP version 3 also supports creating extended-range VLANs in client or
server mode.
Configuring VTP Mode
You can configure VTP mode as one of these:
• When a switch is in VTP server mode, you can change the VLAN configuration and have it
propagated throughout the network.
• When a switch is in VTP client mode, you cannot change its VLAN configuration. The client switch
receives VTP updates from a VTP server in the VTP domain and then modifies its configuration
accordingly.