Vtp Modes - Cisco IE-4000 Software Configuration Manual

Configuring VTP
Information About Configuring VTP

VTP Modes

Table 36 VTP Modes
VTP Mode Description
VTP server In VTP server mode, you can create, modify, and delete VLANs, and specify other configuration parameters
(such as the VTP version) for the entire VTP domain. VTP servers advertise their VLAN configurations to
other switches in the same VTP domain and synchronize their VLAN configurations with other switches
based on advertisements received over trunk links.
VTP server is the default mode.
Note: In VTP server mode, VLAN configurations are saved in NVRAM. If the switch detects a failure while
writing a configuration to NVRAM, VTP mode automatically changes from server mode to client mode. If
this happens, the switch cannot be returned to VTP server mode until the NVRAM is functioning.
VTP client A VTP client behaves like a VTP server and transmits and receives VTP updates on its trunks, but you
cannot create, change, or delete VLANs on a VTP client. VLANs are configured on another switch in the
domain that is in server mode.
In VTP versions 1 and 2, in VTP client mode, VLAN configurations are not saved in NVRAM. In VTP version
3, VLAN configurations are saved in NVRAM in client mode.
VTP transparent VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN
configuration and does not synchronize its VLAN configuration based on received advertisements.
However, in VTP version 2 or version 3, transparent switches do forward VTP advertisements that they
receive from other switches through their trunk interfaces. You can create, modify, and delete VLANs on a
switch in VTP transparent mode.
In VTP versions 1 and 2, the switch must be in VTP transparent mode when you create extended-range
VLANs. VTP version 3 also supports creating extended-range VLANs in client or server mode.
When the switch is in VTP transparent mode, the VTP and VLAN configurations are saved in NVRAM, but
they are not advertised to other switches. In this mode, VTP mode and domain name are saved in the
switch running configuration, and you can save this information in the switch startup configuration file by
using the copy running-config startup-config privileged EXEC command.
VTP off A switch in VTP off mode functions in the same manner as a VTP transparent switch, except that it does
not forward VTP advertisements on trunks.
VTP Mode Guidelines

For VTP version 1 and version 2, if extended-range VLANs are configured on the switch, 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 4096). 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 4096), 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.
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