To enable forward over the Provider network untagged Layer 2 frames received on a vlan-mapping tunnel interface, use the switchport vlan-mapping tunnel l2protocol forward command in Interface (Ethernet, Port Channel) Configuration mode. To restore the default configuration, use the no form of this command.
Syntax
switchport vlan-mapping tunnel l2protocol forward [protocol]
no switchport vlan-mapping tunnel l2protocol forward [protocol]
Parameters
If the protocol argument is not configured then the command is applied to all these protocols.
Default Configuration
The Layer 2 frames are not forwarded.
Command Mode
Interface (Ethernet, Port Channel) Configuration mode
User Guidelines
By default, the switch drops on edge ports input L2 PDUs with the following destination MAC addresses:
Use the switchport vlan-mapping tunnel l2protocol forward command to enable forward over the Provider network untagged frames of a given Layer 2 protocol received on a vlan-mapping
tunnel interface. The received tagged Layer 2 frames are discarded.
When a L2 protocol is forwarded the switch overwrites the customer destination MAC address with a ’well-known’ Multicast address
01:00:0C:CD:CD:D0 before transmission the frame on non-edge port.
When a frame with the destination address equals to this well-known Multicast address is received on non-edge port the switch
forwards it to all non-edge ports belonging to the S_VLAN and to all edge ports belonging to the S-VLAN and configured with
the forward option for the given protocol.
The switch replaces the 'well-known’ destination MAC address with the respective Layer 2 protocol MAC address he respective
Layer 2 protocol MAC address.
CDP cannot be both enabled and also tunneled on the same interfaces. To enable CDP tunneling on a Port Channel interface, CDP first needs to be disabled on all the members of the Port Channel (active and in-active). Likewise, an Ethernet Interface with CDP enabled cannot be added
to a Port Channel on which CDP tunneling is enabled.
LLDP cannot be both enabled and also tunneled on the same interfaces. To enable LLDP tunneling on a Port Channel interface, LLDP first needs to be disabled on all the members of the Port Channel (active and in-active). Likewise, an Ethernet Interface with CDP enabled cannot be added
to a Port Channel on which CDP tunneling is enabled.
If tunnel is defined, use the no switchport vlan-mapping tunnel l2protocol
forward command without the protocol argument to return to the default treatment of all Layer 2 BPDUs.
Use the no switchport vlan-mapping tunnel l2protocol forward command with the protocol argument to return to the default treatment of the specified protocol BPDUs.
Examples
Example 1—The following example specifies that all the 4 protocols (CDP, LLDP, VTP and STP) frames will be forwarded:
switchxxxxxx(config)# interface gi1/0/1
switchxxxxxx(config-if)# switchport vlan-mapping tunnel l2protocol forward
switchxxxxxx(config-if)# exit
Example 2—The following example specifies that only CDP and LLDP protocols frames will be forwarded (Other 2 protocols frames of STP
and VTP will be dropped):
switchxxxxxx(config)# interface gi1/0/1
switchxxxxxx(config-if)# switchport vlan-mapping tunnel l2protocol forward cdp
switchxxxxxx(config-if)# switchport vlan-mapping tunnel l2protocol forward lldp
switchxxxxxx(config-if)# exit
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