Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring VTP
Configuring VTP
•
When you configure the switch for VTP transparent mode, VTP is disabled on the switch. The
switch does not send VTP updates and does not act on VTP updates received from other switches.
However, a VTP transparent switch running VTP version 2 does forward received VTP
advertisements on its trunk links.
• VTP off mode is the same as VTP transparent mode except that VTP advertisements are not
forwarded.
Follow these guidelines:
• For VTP version 1 and version 2, if extended-range VLANs are configured on the switch stack, you
cannot change VTP mode to client or server. You receive an error message, and the configuration is
not allowed. VTP version 1 and version 2 do not propagate configuration information for extended
range VLANs (VLANs 1006 to 4094). You must manually configure these VLANs on each device.
Note
For VTP version 1 and 2, before you create extended-range VLANs (VLAN IDs 1006 to 4094),
you must set VTP mode to transparent by using the
vtp mode transparent global configuration
command. Save this configuration to the startup configuration so that the switch starts in VTP
transparent mode. Otherwise, you lose the extended-range VLAN configuration if the switch
resets and boots up in VTP server mode (the default).
• VTP version 3 supports extended-range VLANs. If extended VLANs are configured, you cannot
convert from VTP version 3 to VTP version 2.
•
If you configure the switch for VTP client mode, the switch does not create the VLAN database file
(vlan.dat). If the switch is then powered off, it resets the VTP configuration to the default. To keep
the VTP configuration with VTP client mode after the switch restarts, you must first configure the
VTP domain name before the VTP mode.
Caution
If all switches are operating in VTP client mode, do not configure a VTP domain name. If you do, it is
impossible to make changes to the VLAN configuration of that domain. Therefore, make sure you
configure at least one switch as a VTP server.
Beginning in privileged EXEC mode, follow these steps to configure the VTP mode:
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
vtp domain domain-name Configure the VTP administrative-domain name. The name can be 1 to 32
characters. All switches operating in VTP server or client mode under the
same administrative responsibility must be configured with the same
domain name.
This command is optional for modes other than server mode. VTP server
mode requires a domain name. If the switch has a trunk connection to a
VTP domain, the switch learns the domain name from the VTP server in the
domain.
You should configure the VTP domain before configuring other VTP
parameters.