Load Sharing Using Stp Path Cost - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 12 Configuring VLANs
Command
Step 6 show vlan
Step 7
configure terminal
Step 8 interface fastethernet 0/1
Step 9 switchport trunk encapsulation {isl |
dot1q | negotiate}
Step 10 switchport mode trunk
Step 11
end
Step 12
show interfaces fastethernet0/1
switchport
Step 13
Step 14
Step 15
show vlan
Step 16
configure terminal
Step 17
interface fastethernet0/1
Step 18
spanning-tree vlan 8 port-priority 10
Step 19 spanning-tree vlan 9 port-priority 10
Step 20
spanning-tree vlan 10 port-priority 10
Step 21
exit
Step 22 interface fastethernet0/2
Step 23 spanning-tree vlan 3 port-priority 10
Step 24
spanning-tree vlan 4 port-priority 10
Step 25
spanning-tree vlan 5 port-priority 10
Step 26 spanning-tree vlan 6 port-priority 10
Step 27
end
Step 28
show running-config
Step 29
copy running-config startup-config

Load Sharing Using STP Path Cost

You can configure parallel trunks to share VLAN traffic by setting different path costs on a trunk and
associating the path costs with different sets of VLANs. The VLANs keep the traffic separate. Because
no loops exist, STP does not disable the ports, and redundancy is maintained in the event of a lost link.
78-11194-09
Purpose
Verify that the VLANs exist in the database on Switch 1.
Enter global configuration mode.
Enter interface configuration mode, and define Fast Ethernet port 0/1
as the interface to be configured as a trunk.
Configure the port to support ISL or 802.1Q encapsulation or to
negotiate with the neighboring interface.
You must configure each end of the link with the same encapsulation
type.
Configure the port as a trunk port.
Return to privilege EXEC mode.
Verify the VLAN configuration.
Repeat Steps 7 through 11 on Switch 1 for Fast Ethernet port 0/2.
Repeat Steps 7 through 11 on Switch 2 to configure the trunk ports on
Fast Ethernet ports 0/1 and 0/2.
When the trunk links come up, VTP passes the VTP and VLAN
information to Switch 2. Verify that Switch 2 has learned the VLAN
configuration.
Enter global configuration mode on Switch 1.
Enter interface configuration mode, and define the interface to set the
STP port priority.
Assign the port priority of 10 for VLAN 8.
Assign the port priority of 10 for VLAN 9.
Assign the port priority of 10 for VLAN 10.
Return to global configuration mode.
Enter interface configuration mode, and define the interface to set the
STP port priority.
Assign the port priority of 10 for VLAN 3.
Assign the port priority of 10 for VLAN 4.
Assign the port priority of 10 for VLAN 5.
Assign the port priority of 10 for VLAN 6.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring VLAN Trunks
12-25