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Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide R8.5
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Chapter 8 Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling on the ML-Series Card
Configuring Layer 2 Protocol Tunneling
• Tunneling is not supported on trunk ports. If you enter the l2protocol-tunnel interface configuration
command on a trunk port, the command is accepted, but Layer 2 tunnelin g does not take effect unless
you change the port to a tunnel port.
• EtherChannel port groups are compatible with tunnel port s as long as the IEEE 802.1Q
configuration is configured within an EtherChannel port grou p.
• If an encapsulated PDU (with the proprietary destination MAC address) is received from a tunnel
port or access port with Layer 2 tunneling enabled, the tun nel port is shut down to prevent loops.
• Only decapsulated PDUs are forwarded to the customer network. The spanning tree instan ce running
on the service-provider network does not forward BPDUs to tunnel ports. No CDP packets are
forwarded from tunnel ports.
• Because tunneled PDUs (especially STP BPDUs) must be delivered to all remote sites for the
customer virtual network to operate properly, you can give PDUs higher priority within the
service-provider network than data packets received from the same tunnel p ort. By default, the
PDUs use the same CoS value as data packets.
• Protocol tunneling has to be configured symmetrically at both the ingress and egress point. For
example, if you configure the entry point to tunnel STP, CDP, and VTP, then you must configure the
egress point in the same way.
Configuring Layer 2 Tunneling on a Port
Beginning in privileged EXEC mode, follow these steps to configure a port as a L ayer 2 tunnel port:
Command Purpose
Step 1 ML_Series# configuration terminal Enters global configuration mode.
Step 2 ML_Series(config)# bridge
bridge-group-number
protocol
type
Creates a bridge group number and specifies a protocol.
Step 3 ML_Series(config)# l2protocol-tunnel cos
cos-value
Associates a CoS value with the Layer 2 tunneling port. Valid numbers
for cos-value range from 0 to 7.
Step 4 ML_Series(config)# interface
type
number
Enters interface configuration mode for the interface to be configured
as a tunnel port.
Step 5 ML_Series(config-if)# bridge-group
bridge-group-number
Assigns a bridge group to the interface.
Step 6 ML_Series(config-if)# mode dot1q tunnel Sets the interface as an IEEE 802.1Q tunnel VLAN.
Step 7 ML_Series(config-if)# l2protocol-tunnel
{all | cdp | stp | vtp}
Sets the interface as a Layer 2 protocol tunnel port and enabl es all
three protocols or specifically enables CDP, STP, or VTP. These
protocols are off by default.
Step 8 ML_Series(config-if)# end Returns to privileged EXEC mode.
Step 9 ML_Series# show dot1q-tunnel Displays the tunnel ports on the switch.
Step 10 ML_Series# copy running-config
startup-config
(Optional) Saves your entries in the configuration file.