Cisco Systems EA6500 Manual De Usuario
14-7
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
78-14099-04
Chapter 14 Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling
Understanding How Layer 2 Protocol Tunneling Works
This example shows how to configure tunneling on port 4/1 and verify the configuration:
Router# configure terminal
Router(config)# interface fastethernet 4/1
Router(config-if)# switchport mode dot1qtunnel
Router(config-if)# end
Router# show dot1q-tunnel interface
Configuring the Switch to Tag Native VLAN Traffic
The vlan dot1q tag native command is a global command that configures the switch to tag native VLAN
traffic, and admit only 802.1Q tagged frames on 802.1Q trunks, dropping any untagged traffic, including
untagged traffic in the native VLAN.
traffic, and admit only 802.1Q tagged frames on 802.1Q trunks, dropping any untagged traffic, including
untagged traffic in the native VLAN.
To configure the switch to tag traffic in the native VLAN, perform this task:
This example shows how to configure the switch to tag native VLAN traffic and verify the configuration:
Router# configure terminal
Router(config)# vlan dot1q tag native
Router(config)# end
Router# show vlan dot1q tag native
Understanding How Layer 2 Protocol Tunneling Works
Layer 2 protocol tunneling allows Layer 2 protocol data units (PDUs) (CDP, STP, and VTP) to be
tunneled through a network. This section uses the following terminology:
tunneled through a network. This section uses the following terminology:
•
Edge switch—The switch connected to the customer switch and placed on the boundary of the
service provider network (see
service provider network (see
•
Layer 2 protocol tunnel port—A port on the edge switch on which a specific tunneled protocol can
be encapsulated or deencapsulated. The Layer 2 protocol tunnel port is configured through CLI
commands.
be encapsulated or deencapsulated. The Layer 2 protocol tunnel port is configured through CLI
commands.
•
Tunneled PDU—A CDP, STP, or VTP PDU.
Without Layer 2 protocol tunneling, tunnel ports drop STP and VTP packets and process CDP packets. This
handling of the PDUs creates different spanning tree domains (different spanning tree roots) for the
customer switches. For example, STP for a VLAN on switch 1 (see
handling of the PDUs creates different spanning tree domains (different spanning tree roots) for the
customer switches. For example, STP for a VLAN on switch 1 (see
) builds a spanning tree
Step 4
Router(config-if)# end
Exits configuration mode.
Step 5
Router# show dot1q-tunnel [{interface type
interface-number}]
Verifies the configuration.
1.
type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Command
Purpose
Command
Purpose
Step 1
Router(config)# vlan dot1q tag native
Configures the switch to tag native VLAN traffic.
Router(config)# no vlan dot1q tag native
Clears the configuration.
Step 2
Router(config)# end
Exits configuration mode.
Step 3
Router# show vlan dot1q tag native
Verifies the configuration.