Client Mode - Cisco WS-C6506 Software Manual

Understanding How VTP Version 3 Works
Switches running VTP version 3 have the following common characteristics:
•
•
•
•
VTP version 3 modes are described in the following sections:
•
•
•
For more information on configuring modes, see the
page

Client Mode

VTP version 3 clients are similar to VTP version 1 and VTP version 2 clients as follows:
•
•
•
Server Mode
Primary and secondary servers are two types of servers that may exist on a VLAN or VTP instance in
the VTP domain.
Secondary Server
When a switch is configured to be a server, it becomes a secondary server by default. As a secondary
server, a VTP version 3 switch behaves as a client with the following exceptions:
•
•
•
•
•
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
10-18
They accept only VTP packets from the same VTP domain.
If they do not have a primary server, they accept the primary server that is associated with the first
VTP database that they receive for any instance.
They accept only a database with a higher revision number from their current primary server.
If they have a password configured (whether hidden or not hidden), they accept only a new database
or a takeover message if it contains the correct password.
Client Mode, page 10-18
Server Mode, page 10-18
Transparent and VTP Off Modes, page 10-19
10-23.
A VTP client accepts a VTP configuration from the network but cannot generate or alter the
configuration.
A VTP client stores the VTP configuration that it receives in RAM (not NVRAM). When a VTP
client boots, it needs to reacquire the entire configuration that is propagated by VTP, including the
identity of the primary server.
A VTP client that cannot store the entire VTP configuration that is received in an instance to RAM,
immediately transitions to transparent mode.
A secondary server immediately stores the information that is received through VTP version 3 in
NVRAM. This NVRAM is part of the running configuration or startup configuration.
At startup, a secondary server that has a configuration in NVRAM starts advertising the
configuration. The main purpose of a VTP secondary server is to back up the configuration that is
propagated over the network.
Similar to a client, a VTP secondary server cannot modify the VTP configuration.
A VTP server reverts to client mode if it cannot store the configuration in NVRAM.
A VTP version 3 secondary server can issue a takeover to become a primary server.
Chapter 10
"Changing VTP Version 3 Modes" section on
Configuring VTP
OL-8978-04