Configuring 802.1Q Tunneling
Preconfiguration Tasks
Before you can configure Layer 2 protocol tunneling, you must perform these tasks:
On all the service provider edge switches, PortFast BPDU filtering must be enabled on the 802.1Q tunnel
Step 1
ports as follows:
At least one VLAN must be available for Native VLAN tagging (vlan dot1q tag native option). If you
Step 2
use all the available VLANs and then try to enable the vlan dot1q tag native option, the option will not
be enabled.
On all the service provider core switches, tag native VLAN egress traffic and drop untagged native
Step 3
VLAN ingress traffic by entering the following command:
Router(config)# vlan dot1q tag native
On all the customer switches, either enable or disable the global vlan dot1q tag native option.
Step 4
Configuring 802.1Q Tunnel Ports
To configure 802.1Q tunneling on a port, perform this task:
Command
Step 1
Router(config)# interface type
Step 2
Router(config-if)# switchport
Step 3
Router(config-if)# switchport mode dot1qtunnel
Router(config-if)# no switchport mode dot1qtunnel
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
14-6
Router(config-if)# spanning-tree bpdufilter enable
Router(config-if)# spanning-tree portfast
With Release 12.1(13)E and later releases, PortFast BPDU filtering is enabled automatically
Note
on tunnel ports. With releases earlier than Release 12.1(13)E, you must manually enable
PortFast BPDU filtering on tunnel ports.
If this option is enabled on one switch and disabled on another switch, all traffic is dropped;
Note
all customer switches must have this option configured the same on each switch.
1
slot/port
Chapter 14
Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling
Purpose
Selects the LAN port to configure.
Configures the LAN port for Layer 2 switching:
You must enter the switchport command once
•
without any keywords to configure the LAN port as a
Layer 2 interface before you can enter additional
switchport commands with keywords.
Required only if you have not entered the switchport
•
command already for the interface.
Configures the Layer 2 port as a tunnel port.
Clears the tunnel port configuration.
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