Figure 4: Load Sharing by Using STP Port Priorities
Trunk1 carries traffic for VLANs 8 through 10, and Trunk 2 carries traffic for VLANs 3 through 6. If the
activetrunk fails, the trunk with the lower priority takes over and carries the traffic for all of the VLANs. No
duplicationof traffic occurs over any trunk port.
Related Topics
ConfiguringLoad Sharing Using STPPort Priorities, on page73
Network Load Sharing Using STP Path Cost
Youcan configure parallel trunks to share VLAN trafficby setting different path costs on a trunk and associating
thepath costs with different sets of VLANs, blocking different ports for different VLANs. The VLANs keep
thetraffic separate and maintain redundancy in the event of a lost link.
Trunkports 1 and 2 are configured as 100BASE-T ports. These VLAN path costs are assigned:
•VLANs2 through 4 are assigned a path cost of 30 on Trunk port 1.
•VLANs8 through 10 retain the default 100BASE-T path cost on Trunk port 1 of 19.
•VLANs8 through 10 are assigned a path cost of 30 on Trunk port 2.
•VLANs2 through 4 retain the default 100BASE-T path cost on Trunk port 2 of 19.
Figure 5: Load-Sharing Trunks with Traffic Distributed by Path Cost
Related Topics
ConfiguringLoad Sharing Using STPPath Cost, on page 77
Catalyst 2960-XR Switch VLAN Configuration Guide, Cisco IOS Release 15.0(2)EX1
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Configuring VLAN Trunks
Load Sharing on Trunk Ports