Cisco 7604 User Manual

10-8
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 10 Configuring LAN Ports for Layer 2 Switching
Configuring LAN Interfaces for Layer 2 Switching
Configuring a Layer 2 Switching Port as a Trunk
These section describe configuring a Layer 2 switching port as a trunk:
• Configuring the Layer 2 Switching Port as an ISL or 802.1Q Trunk, page 10-8
• Configuring the Layer 2 Trunk to Use DTP, page 10-9
• Configuring the Layer 2 Trunk Not to Use DTP, page 10-9
• Configuring the Access VLAN, page 10-10
• Configuring the 802.1Q Native VLAN, page 10-10
• Configuring the List of VLANs Allowed on a Trunk, page 10-11
• Configuring the List of Prune-Eligible VLANs, page 10-11
• Completing Trunk Configuration, page 10-12
• Verifying Layer 2 Trunk Configuration, page 10-12
• Configuration and Verification Examples, page 10-13
Configuring the Layer 2 Switching Port as an ISL or 802.1Q Trunk
Note • Complete the steps in the “Configuring a LAN Port for Layer 2 Switching” section on page 10-7
before performing the tasks in this section.
• When you enter the switchport command with no other keywords (Step 3 in the previous section),
the default mode is switchport mode dynamic desirable and switchport trunk encapsulation
negotiate.
To configure the Layer 2 switching port as an ISL or 802.1Q trunk, perform this task:
When configuring the Layer 2 switching port as an ISL or 802.1Q trunk, note the following information:
• The switchport mode trunk command (see the “Configuring the Layer 2 Trunk Not to Use DTP”
section on page 10-9) is not compatible with the switchport trunk encapsulation negotiate
command.
• To support the switchport mode trunk command, you must configure the encapsulation as either
ISL or 802.1Q.
• The following switching modules do not support ISL encapsulation:
– WS-X6502-10GE
– WS-X6548-GE-TX, WS-X6548V-GE-TX, WS-X6548-GE-45AF
– WS-X6148-GE-TX, WS-X6148V-GE-TX, WS-X6148-GE-45AF
Command Purpose
Router(config-if)# switchport trunk encapsulation
{isl | dot1q | negotiate}
(Optional) Configures the encapsulation, which configures
the Layer 2 switching port as either an ISL or 802.1Q trunk.
Router(config-if)# no switchport trunk encapsulation
Reverts to the default trunk encapsulation mode (negotiate).

Cisco 7604 Specifications

General

Brand	Cisco
Model	7604
Category	Network Router
Language	English