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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 5 Configuring Ethernet VLAN Trunks
Example VLAN Trunk Configurations
Switch_1> (enable)
show spantree 1/2
Port Vlan Port-State Cost Priority Fast-Start Group-method
--------- ---- ------------- ----- -------- ---------- ------------
1/2 1 blocking 19 32 disabled
1/2 10 blocking 19 32 disabled
1/2 20 blocking 19 32 disabled
1/2 30 blocking 19 32 disabled
1/2 40 blocking 19 32 disabled
1/2 50 blocking 19 32 disabled
1/2 60 blocking 19 32 disabled
1/2 1003 not-connected 19 32 disabled
1/2 1005 not-connected 19 4 disabled
Switch_1> (enable)
Step 8
Divide the configured VLANs into two groups. You might want traffic from half of the VLANs to go
over one trunk link and half over the other, or if one VLAN has heavier traffic than the others, you can
forward traffic from that VLAN over one trunk and traffic from the other VLANs over the other trunk
link.
Note
In the following steps, VLANs 10, 20, and 30 (Group 1) are forwarded over Trunk 1, and
VLANs 40, 50, and 60 (Group 2) are forwarded over Trunk 2.
Step 9
On Switch 1, change the port-VLAN priority for the Group 1 VLANs on Trunk 1 (port 1/1) to an integer
value lower than the default of 32 by entering the
set spantree portvlanpri
command.
Switch_1> (enable)
set spantree portvlanpri 1/1 1 10
Port 1/1 vlans 1-9,11-1004 using portpri 32.
Port 1/1 vlans 10 using portpri 1.
Port 1/1 vlans 1005 using portpri 4.
Switch_1> (enable)
set spantree portvlanpri 1/1 1 20
Port 1/1 vlans 1-9,11-19,21-1004 using portpri 32.
Port 1/1 vlans 10,20 using portpri 1.
Port 1/1 vlans 1005 using portpri 4.
Switch_1> (enable)
set spantree portvlanpri 1/1 1 30
Port 1/1 vlans 1-9,11-19,21-29,31-1004 using portpri 32.
Port 1/1 vlans 10,20,30 using portpri 1.
Port 1/1 vlans 1005 using portpri 4.
Switch_1> (enable)
Step 10
On Switch 1, change the port-VLAN priority for the Group 2 VLANs on Trunk 2 (port 1/2) to an integer
value lower than the default of 32 by entering the
set spantree portvlanpri
command.
Switch_1> (enable)
set spantree portvlanpri 1/2 1 40
Port 1/2 vlans 1-39,41-1004 using portpri 32.
Port 1/2 vlans 40 using portpri 1.
Port 1/2 vlans 1005 using portpri 4.
Switch_1> (enable)
set spantree portvlanpri 1/2 1 50
Port 1/2 vlans 1-39,41-49,51-1004 using portpri 32.
Port 1/2 vlans 40,50 using portpri 1.
Port 1/2 vlans 1005 using portpri 4.
Switch_1> (enable)
set spantree portvlanpri 1/2 1 60
Port 1/2 vlans 1-39,41-49,51-59,61-1004 using portpri 32.
Port 1/2 vlans 40,50,60 using portpri 1.
Port 1/2 vlans 1005 using portpri 4.
Switch_1> (enable)