Cisco Catalyst 3750 Software Configuration Manual page 229

Chapter 10 Configuring VLANs
Figure 10-4 Load-Sharing Trunks with Traffic Distributed by Path Cost
VLANs 2 – 4 (path cost 30)
VLANs 8 – 10 (path cost 19)
Beginning in privileged EXEC mode, follow these steps to configure the network shown in
Command
Step 1 configure terminal
Step 2
interface gigabitethernet1/0/1
Step 3
switchport trunk encapsulation
{isl | dot1q | negotiate}
Step 4
switchport mode trunk
Step 5 exit
Step 6
Step 7
end
Step 8 show running-config
Step 9 show vlan
Step 10 configure terminal
Step 11
interface gigabitethernet1/0/1
Step 12
spanning-tree vlan 2-4 cost 30
Step 13
end
Step 14
Step 15 exit
Step 16
show running-config
Step 17
copy running-config startup-config
78-15870-01
Switch A
Trunk port 1 Trunk port 2
VLANs 8 – 10 (path cost 30)
VLANs 2 – 4 (path cost 19)
Switch B
Purpose
Enter global configuration mode on Switch A.
Enter interface configuration mode, and define Gigabit Ethernet port 1
as the interface to be configured as a trunk.
Configure the port to support ISL or 802.1Q encapsulation. You must
configure each end of the link with the same encapsulation type.
Configure the port as a trunk port.
The trunk defaults to ISL trunking.
Return to global configuration mode.
Repeat Steps 2 through 4 on a second interface in Switch A.
Return to privileged EXEC mode.
Verify your entries. In the display, make sure that the interfaces
configures in Steps 2 and 6 are configured as trunk ports.
When the trunk links come up, Switch A receives the VTP information
from the other switches. Verify that Switch A has learned the VLAN
configuration.
Enter global configuration mode.
Enter interface configuration mode, and define Gigabit Ethernet port 1
as the interface on which to set the STP cost.
Set the spanning-tree path cost to 30 for VLANs 2 through 4.
Return to global configuration mode.
Repeat Steps 9 through 11 on the other configured trunk interface on
Switch A, and set the spanning-tree path cost to 30 for VLANs 8, 9, and
10.
Return to privileged EXEC mode.
Verify your entries. In the display, verify that the path costs are set
correctly for both trunk interfaces.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Metro Switch Software Configuration Guide
Configuring VLAN Trunks
Figure 10-4:
10-27