Cisco 6500 Series Software Configuration Manual page 109

Chapter 7 Configuring LAN Ports for Layer 2 Switching
Configuring the Layer 2 Switching Port as an ISL or 802.1Q Trunk
Complete the steps in the
Note
page 7-8
To configure the Layer 2 switching port as an ISL or 802.1Q trunk, perform this task:
Command
Router(config-if)# switchport trunk encapsulation
{isl | dot1q | negotiate}
Router(config-if)# no switchport trunk encapsulation
Complete the steps in the
Note
tasks in this section.
Configuring the Layer 2 Trunk to Use DTP
Complete the steps in the
Note
page 7-8
To configure the Layer 2 trunk to use DTP, perform this task:
Command
Router(config-if)# switchport mode dynamic {auto |
desirable}
Router(config-if)# no switchport mode
When configuring the Layer 2 trunk to use DTP, note the following syntax information:
•
•
Note Complete the steps in the
tasks in this section.
78-14099-04
"Preparing a Layer 2 Switching Port for Configuration as a Trunk" section on
before performing the tasks in this section.
"Completing Trunk Configuration" section on page 7-13
"Preparing a Layer 2 Switching Port for Configuration as a Trunk" section on
before performing the tasks in this section.
Required only if the interface is a Layer 2 access port or to specify the trunking mode.
See Table 7-2 on page 7-4
"Completing Trunk Configuration" section on page 7-13
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
Purpose
(Optional) Configures the encapsulation, which configures
the Layer 2 switching port as either an ISL or 802.1Q trunk.
To support the switchport mode trunk command,
Note
you must configure the encapsulation.
Reverts to the default trunk encapsulation mode (negotiate).
Purpose
(Optional) Configures the trunk to use DTP.
Reverts to the default trunk trunking mode (switchport mode
dynamic desirable).
for information about trunking modes.
Configuring LAN Interfaces for Layer 2 Switching
after performing the
after performing the
7-9