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Catalyst 3560 Switch Software Configuration Guide
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Chapter 13 Configuring VLANs
Configuring VLAN Trunks
In this way, Trunk 1 carries traffic for VLANs 8 through 10, and Trunk 2 carries traffic for VLANs 3
through 6. If the active trunk fails, the trunk with the lower priority takes over and carries the traffic for
all of the VLANs. No duplication of traffic occurs over any trunk port.
Figure 13-3 Load Sharing by Using STP Port Priorities
Beginning in privileged EXEC mode, follow these steps to configure the network shown in Figure 13-3.
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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 Operating 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 gigabitethernet 0/1
switchport
Verify the VLAN configuration.
Step 13 Repeat Steps 7 through 11 on Switch A for a second port in the switch.
Step 14 Repeat Steps 7 through 11 on Switch B to configure the trunk ports
that connect to the trunk ports configured on Switch A.
Step 15 show vlan When the trunk links come up, VTP passes the VTP and VLAN
information to Switch B. Verify that Switch B has learned the VLAN
configuration.
Step 16 configure terminal Enter global configuration mode on Switch A.