Cisco Catalyst 3750-X User Manual

15-23
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 15 Configuring VLANs
Configuring VLAN Trunks
Figure 15-3 Load Sharing by Using STP Port Priorities
Note If your switch is a member of a switch stack, you must use the spanning-tree [vlan vlan-id] cost cost
interface configuration command instead of the spanning-tree [vlan vlan-id] port-priority priority
interface configuration command to select an interface to put in the forwarding state. Assign lower cost
values to interfaces that you want selected first and higher cost values that you want selected last. For
more information, see the “Load Sharing Using STP Path Cost” section on page 15-24.
Beginning in privileged EXEC mode, follow these steps to configure the network shown in Figure 15-3.
93370
Switch A
Switch B
Trunk 2
VLANs 3 – 6 (priority 16)
VLANs 8 – 10 (priority 128)
Trunk 1
VLANs 8 – 10 (priority 16)
VLANs 3 – 6 (priority 128)
Command Purpose
Step 1
configure terminal Enter global configuration mode on Switch A.
Step 2
vtp domain domain-name Configure a VTP administrative domain.
The domain name can be 1 to 32 characters.
Step 3
vtp mode server Configure Switch A as the VTP server.
Step 4
end Return to privileged EXEC mode.
Step 5
show vtp status Verify the VTP configuration on both Switch A and Switch B.
In the display, check the VTP Op
erating Mode and the VTP Domain
Name fields.
Step 6
show vlan Verify that the VLANs exist in the database on Switch A.
Step 7
configure terminal Enter global configuration mode.
Step 8
interface gigabitethernet 0/1 Define the interface to be configured as a trunk, and enter interface
configuration mode.
Step 9
switchport trunk encapsulation {isl |
dot1q | negotiate}
Configure the port to support ISL or IEEE 802.1Q encapsulation or to
negotiate with the neighboring interface. You must configure each end
of the link with the same encapsulation type.
Step 10
switchport mode trunk Configure the port as a trunk port.
Step 11
end Return to privileged EXEC mode.
Step 12
show interfaces gigabitethernet1/ 0/1
switchport
Verify the VLAN configuration.
Step 13
Repeat Steps 7 through 11on Switch A for a second port in the switch
or switch stack.
Step 14
Repeat Steps 7 through 11on Switch B to configure the trunk ports that
connect to the trunk ports configured on Switch A.

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing