L2Protocol-Tunnel - Cisco Catalyst 4500 Series Command Reference Manual

l2protocol-tunnel

l2protocol-tunnel
To enable protocol tunneling on an interface, use the l2protocol-tunnel command. You can enable
tunneling for the Cisco Discovery Protocol (CDP), Spanning Tree Protocol (STP), or VLAN Trunking
Protocol (VTP) packets. To disable tunneling on the interface, use the no form of this command.
Syntax Description
cdp
stp
vtp
Defaults
The default is that no Layer 2 protocol packets are tunneled.
Command Modes
Interface configuration mode
Command History Release
12.2(18)EW
Usage Guidelines
You must enter this command, with or without protocol types, to tunnel Layer 2 packets.
Layer 2 protocol tunneling across a service-provider network ensures that Layer 2 information is
propagated across the network to all customer locations. When protocol tunneling is enabled, protocol
packets are encapsulated with a well-known Cisco multicast address for transmission across the network.
When the packets reach their destination, the well-known MAC address is replaced by the Layer 2
protocol MAC address.
You can enable Layer 2 protocol tunneling for CDP, STP, and VTP individually or for all three protocols.
Examples This example shows how to enable protocol tunneling for the CDP packets:
Switch(config-if)# l2protocol-tunnel cdp
Switch(config-if)#
Related Commands Command
l2protocol-tunnel cos
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0SG and IOS 15.1(1)SG)
2-372
l2protocol-tunnel [cdp | stp | vtp]
no l2protocol-tunnel [cdp | stp | vtp]
(Optional) Enables tunneling of CDP.
(Optional) Enables tunneling of STP.
(Optional) Enables tunneling of VTP.
Modification
Support for this command was introduced on the Catalyst 4500 series switch.
Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
Description
Configures the class of service (CoS) value for all tunneled
Layer 2 protocol packets.
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