Cisco Systems 3750E Manual De Usuario
13-27
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02
Chapter 13 Configuring VLANs
Configuring VLAN Trunks
Figure 13-4
Load-Sharing Trunks with Traffic Distributed by Path Cost
Beginning in privileged EXEC mode, follow these steps to configure the network shown in
:
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
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 gigabitethernet1/0/1
Define the interface to be configured as a trunk, and enter interface
configuration mode.
configuration mode.
Step 3
switchport trunk encapsulation
{isl | dot1q | negotiate}
{isl | dot1q | negotiate}
Configure the port to support ISL or IEEE 802.1Q encapsulation. You
must configure each end of the link with the same encapsulation type.
must configure each end of the link with the same encapsulation type.
Step 4
switchport mode trunk
Configure the port as a trunk port. The trunk defaults to ISL trunking.
Step 5
exit
Return to global configuration mode.
Step 6
Repeat Steps 2 through 5 on a second interface in Switch A (for a
Catalyst 3560-E switch) or in the Switch A stack (for a Catalyst 3750-E
switch).
Catalyst 3560-E switch) or in the Switch A stack (for a Catalyst 3750-E
switch).
Step 7
end
Return to privileged EXEC mode.
Step 8
show running-config
Verify your entries. In the display, make sure that the interfaces are
configured as trunk ports.
configured as trunk ports.
Step 9
show vlan
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.
from the other switches. Verify that Switch A has learned the VLAN
configuration.
Step 10
configure terminal
Enter global configuration mode.
Step 11
interface gigabitethernet1/0/1
Define the interface on which to set the STP cost, and enter interface
configuration mode.
configuration mode.
Step 12
spanning-tree vlan 2-4 cost 30
Set the spanning-tree path cost to 30 for VLANs 2 through 4.
Step 13
end
Return to global configuration mode.
Step 14
Repeat Steps 9 through 13 on the other configured trunk interface on
Switch A, and set the spanning-tree path cost to 30 for VLANs 8, 9, and
10.
Switch A, and set the spanning-tree path cost to 30 for VLANs 8, 9, and
10.
Step 15
exit
Return to privileged EXEC mode.
Step 16
show running-config
Verify your entries. In the display, verify that the path costs are set
correctly for both trunk interfaces.
correctly for both trunk interfaces.
Step 17
copy running-config startup-config
(Optional) Save your entries in the configuration file.