Cisco 6500 Series Software Configuration Manual page 122

Understanding How VTP Works
Figure 8-1
and port 2 on Switch 4 are assigned to the Red VLAN. A broadcast is sent from the host connected to
Switch 1. Switch 1 floods the broadcast, and every network device in the network receives it, even
though Switches 3, 5, and 6 have no ports in the Red VLAN.
You enable pruning globally on the Catalyst 6500 series switch (see the
on page
Switching Port as a Trunk" section on page
Figure 8-1
Catalyst series
Switch 6
Figure 8-2
Switch 1 is not forwarded to Switches 3, 5, and 6 because traffic for the Red VLAN has been pruned on
the links indicated (port 5 on Switch 2 and port 4 on Switch 4).
Figure 8-2
Flooded traffic
is pruned.
Switch 5
Switch 6
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
8-4
shows a switched network without VTP pruning enabled. Interface 1 on network Switch 1
8-7). You configure pruning on Layer 2 trunking LAN ports (see the
Flooding Traffic without VTP Pruning
Catalyst series
Switch 4
Catalyst series
Catalyst series
Switch 5
Catalyst series
Switch 3
shows the same switched network with VTP pruning enabled. The broadcast traffic from
Flooding Traffic with VTP Pruning
Switch 4
Interface 2
Interface 4
Switch 2
Interface 5
Switch 3 Switch 1
7-8).
Interface 2
Switch 2
Red
VLAN
Interface 1
Catalyst series
Switch 1
Red
VLAN
Interface 1
Chapter 8 Configuring VTP
"Enabling VTP Pruning" section
"Configuring a Layer 2
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