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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 9 Creating and Maintaining VLANs
Using the VLAN Trunking Protocol
Enabling VTP Pruning
Pruning increases available bandwidth by restricting flooded traffic to those trunk links that the traffic
must use to access the destination devices. You enable VTP pruning on a switch in VTP server mode.
Beginning in privileged EXEC mode, follow these steps to enable VTP pruning in the management
domain:
Pruning is supported with VTP version 1 and version 2. If you enable pruning on the VTP server, it is
enabled for the entire VTP domain.
Only VLANs included in the pruning-eligible list can be pruned. By default, VLANs 2 through 1001 are
pruning eligible on trunk ports. To change the pruning-eligible VLANs, see the
“Changing the
Pruning-Eligible List” section on page 9-28
.
To disable VTP pruning, use the no vtp pruning VLAN configuration command.
Monitoring VTP
You monitor VTP by displaying VTP configuration information: the domain name, the current VTP
revision, and the number of VLANs. You can also display statistics about the advertisements sent and
received by the switch.
Beginning in privileged EXEC mode, follow these steps to monitor VTP activity:
Command
Purpose
Step 1
vlan database
Enter VLAN configuration mode.
Step 2
vtp pruning
Enable pruning in the VTP administrative domain.
By default, pruning is disabled. You need to enable pruning on only one
switch in VTP server mode.
Step 3
exit
Update the VLAN database, propagate it throughout the administrative
domain, and return to privileged EXEC mode.
Step 4
show vtp status
Verify your entries in the VTP Pruning Mode field of the display.
Table 9-4
VTP Monitoring Commands
Command
Purpose
show vtp status
Display the VTP switch configuration information.
show vtp counters
Display counters about VTP messages that have been sent and received.