Configuring A Layer 2 Switching Port As A Trunk - Cisco 7604 Configuration Manual

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
Note •
•
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
When configuring the Layer 2 switching port as an ISL or 802.1Q trunk, note the following information:
•
•
•
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
10-8
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
Complete the steps in the
before performing the tasks in this section.
When you enter the switchport command with no other keywords
the default mode is switchport mode dynamic desirable and switchport trunk encapsulation
negotiate.
The switchport mode trunk command (see the
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
Chapter 10
"Configuring a LAN Port for Layer 2 Switching" section on page 10-7
Purpose
(Optional) Configures the encapsulation, which configures
the Layer 2 switching port as either an ISL or 802.1Q trunk.
Reverts to the default trunk encapsulation mode (negotiate).
"Configuring the Layer 2 Trunk Not to Use DTP"
Configuring LAN Ports for Layer 2 Switching
(Step 3 in the previous section),
OL-4266-08