Chapter 15
Configuring VLANs
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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 15-2
VLANs 8 – 10 (priority 16)
VLANs 3 – 6 (priority 128)
Beginning in privileged EXEC mode, follow these steps to configure the network shown in
Command
Step 1
configure terminal
Step 2
vtp domain domain-name
Step 3
vtp mode server
Step 4
end
Step 5
show vtp status
Step 6
show vlan
Step 7
configure terminal
Step 8
interface gigabitethernet 0/1
Step 9
switchport mode trunk
Step 10
end
Step 11
show interfaces gigabitethernet 0/1
switchport
Step 12
Step 13
Step 14
show vlan
Step 15
configure terminal
OL-13018-03
VLANs 3 through 6 are assigned a port priority of 16 on Trunk 2.
VLANs 8 through 10 retain the default port priority of 128 on Trunk 2.
Load Sharing by Using STP Port Priorities
Trunk 1
Switch B
Switch A
Trunk 2
VLANs 3 – 6 (priority 16)
VLANs 8 – 10 (priority 128)
Purpose
Enter global configuration mode on Switch A.
Configure a VTP administrative domain.
The domain name can be 1 to 32 characters.
Configure Switch A as the VTP server.
Return to privileged EXEC mode.
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.
Verify that the VLANs exist in the database on Switch A.
Enter global configuration mode.
Define the interface to be configured as a trunk, and enter interface
configuration mode.
Configure the port as a trunk port.
Return to privileged EXEC mode.
Verify the VLAN configuration.
Repeat Steps 7 through 10 on Switch A for a second port in the switch.
Repeat Steps 7 through 10 on Switch B to configure the trunk ports
that connect to the trunk ports configured on Switch A.
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.
Enter global configuration mode on Switch A.
Cisco IE 3000 Switch Software Configuration Guide
Configuring VLAN Trunks
Figure
15-2.
15-21