Cisco IE-3000-8TC User Manual

15-22
Cisco IE 3000 Switch Software Configuration Guide
OL-13018-03
Chapter 15 Configuring VLANs
Configuring VLAN Trunks
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, blocking different ports for different VLANs.
The VLANs keep the traffic separate and maintain redundancy in the event of a lost link.
In Figure 15-3, Trunk ports 1 and 2 are configured as 100BASE-T ports. These VLAN path costs are
assigned:
• VLANs 2 through 4 are assigned a path cost of 30 on Trunk port 1.
• VLANs 8 through 10 retain the default 100BASE-T path cost on Trunk port 1 of 19.
• VLANs 8 through 10 are assigned a path cost of 30 on Trunk port 2.
• VLANs 2 through 4 retain the default 100BASE-T path cost on Trunk port 2 of 19.
Figure 15-3 Load-Sharing Trunks with Traffic Distributed by Path Cost
Beginning in privileged EXEC mode, follow these steps to configure the network shown in Figure 15-3:
Step 16
interface gigabitethernet 0/1 Define the interface to set the STP port priority, and enter interface
configuration mode.
Step 17
spanning-tree vlan 8-10 port-priority 16 Assign the port priority of 16 for VLANs 8 through 10.
Step 18
exit Return to global configuration mode.
Step 19
interface gigabitethernet0/2 Define the interface to set the STP port priority, and enter interface
configuration mode.
Step 20
spanning-tree vlan 3-6 port-priority 16 Assign the port priority of 16 for VLANs 3 through 6.
Step 21
end Return to privileged EXEC mode.
Step 22
show running-config Verify your entries.
Step 23
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
90573
Switch A
Switch B
Trunk port 1
VLANs 2 – 4 (path cost 30)
VLANs 8 – 10 (path cost 19)
Trunk port 2
VLANs 8 – 10 (path cost 30)
VLANs 2 – 4 (path cost 19)
Command Purpose
Step 1
configure terminal Enter global configuration mode on Switch A.
Step 2
interface gigabitethernet0/1 Define the interface to be configured as a trunk, and enter interface
configuration mode.
Step 3
switchport mode trunk Configure the port as a trunk port.

Cisco IE-3000-8TC Specifications

General

Brand	Cisco
Model	IE-3000-8TC
Category	Switch
Language	English