Cisco 3750G - Catalyst Integrated Wireless LAN Controller User Manual

14-5
Catalyst 3750 Switch Software Configuration Guide
OL-8550-02
Chapter 14 Configuring VTP
Understanding VTP
VTP pruning blocks unneeded flooded traffic to VLANs on trunk ports that are included in the
pruning-eligible list. Only VLANs included in the pruning-eligible list can be pruned. By default,
VLANs 2 through 1001 are pruning eligible switch trunk ports. If the VLANs are configured as
pruning-ineligible, the flooding continues. VTP pruning is supported with VTP Version 1 and Version 2.
Figure 14-1 shows a switched network without VTP pruning enabled. Port 1 on Switch A and Port 2 on
Switch D are assigned to the Red VLAN. If a broadcast is sent from the host connected to Switch A,
Switch A floods the broadcast and every switch in the network receives it, even though Switches C, E,
and F have no ports in the Red VLAN.
Figure 14-1 Flooding Traffic without VTP Pruning
Figure 14-2 shows a switched network with VTP pruning enabled. The broadcast traffic from Switch A
is not forwarded to Switches C, E, and F because traffic for the Red VLAN has been pruned on the links
shown (Port 5 on Switch B and Port 4 on Switch D).
Figure 14-2 Optimized Flooded Traffic with VTP Pruning
Switch D
Switch E
Switch CSwitch F Switch A
Switch B
Port 1
Port 2
Red
VLAN
89240
Switch D
Switch E
Switch CSwitch F Switch A
Switch B
Port 1
Port 2
Red
VLAN
89241
Port
4
Flooded traffic
is pruned.
Port
5
Flooded traffic
is pruned.

Cisco 3750G - Catalyst Integrated Wireless LAN Controller Specifications

General

Switching Capacity	32 Gbps
RAM	128 MB
Flash Memory	32 MB
Power Device	Internal power supply
Ports	48 x 10/100/1000 + 4 x SFP
Performance	38.7 Mpps
Wireless LAN Controller Capacity	50
Stacking	Yes
Features	VLAN support, QoS
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.3ab, IEEE 802.3z
Operating Humidity	10% to 85% non-condensing
Power over Ethernet (PoE)	Yes (optional)