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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 16 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 16-3 Load Sharing by Using STP Port Priorities
Beginning in privileged EXEC mode, follow these steps to configure the network shown in Figure 16-3.
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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 1.
Step 2 vtp domain domain-name Configure a VTP administrative domain.
The domain name can be from 1 to 32 characters.
Step 3 vtp mode server Configure Switch 1 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 Enter interface configuration mode, and define as the interface to be
configured as a trunk.
Step 9 switchport mode trunk Configure the port as a trunk port.
Step 10 end Return to privilege EXEC mode.
Step 11 show interfaces switchport Verify the VLAN configuration.
Step 12 Repeat Steps 7 through 11 on Switch A for .
Step 13 Repeat Steps 7 through 11 on Switch B to configure the trunk ports on
.
Step 14 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 15 configure terminal Enter global configuration mode on Switch A.
Step 16 interface Enter interface configuration mode, and define the interface to set the
STP port priority.
Step 17 spanning-tree vlan 8-10 port-priority 16 Assign the port priority of 16 for VLANs 8 through 10.