Cisco Catalyst 4500 Series Configuration Guide

27-17
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
OL-25340-01
Chapter 27 Configuring 802.1Q Tunneling, VLAN Mapping, and Layer 2 Protocol Tunneling
Configuring Layer 2 Protocol Tunneling
• Because tunneled PDUs (especially STP BPDUs) must be delivered to all remote sites so that the
customer virtual network operates properly, you can give PDUs higher priority within the service
provider network than data packets received from the same tunnel port. By default, the PDUs use
the same CoS value as data packets.
Note If Layer 2 protocol tunneling is not configured on a system, Layer 2 protocol tunneling packets
are handled as data packets and this situation does not apply.
Configuring Layer 2 Tunneling
To configure a port for Layer 2 protocol tunneling, perform this task:
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(config)# interface
interface-id
Enters interface configuration mode, and enter the interface to be
configured as a tunnel port. This should be the edge port in the service
provider network that connects to the customer switch. Valid interfaces can
be physical interfaces and port-channel logical interfaces (port channels 1
to 64).
Step 3
Switch(config-if)# switchport
mode access
or
Switch(config-if)# switchport
mode dot1q-tunnel
or
Switch(config-if)# switchport
mode trunk
Configures the interface as an access port, an 802.1Q tunnel port or a trunk
port.
Step 4
Switch(config-if)#
l2protocol-tunnel
[cdp | stp | vtp]
Enables protocol tunneling for the desired protocol. If no keyword is
entered, tunneling is enabled for all three Layer 2 protocols.
Step 5
Switch(config-if)#
l2protocol-tunnel
shutdown-threshold
[cdp | stp | vtp]
value
(Optional) Configures the threshold for packets-per-second accepted for
encapsulation. The interface is disabled if the configured threshold is
exceeded. If no protocol option is specified, the threshold applies to each of
the tunneled Layer 2 protocol types. The range is 1 to 4096. The default is
to have no threshold configured.
Note If you also set a drop threshold on this interface, the
shutdown-threshold value must be greater than or equal to the
drop-threshold value.
Step 6
Switch(config-if)#
l2protocol-tunnel drop-threshold
[cdp | stp | vtp] value
(Optional) Configures the threshold for packets-per-second accepted for
encapsulation. The interface drops packets if the configured threshold is
exceeded. If no protocol option is specified, the threshold applies to each of
the tunneled Layer 2 protocol types. The range is 1 to 4096. The default is
to have no threshold configured.
Note If you also set a shutdown threshold on this interface, the
drop-threshold value must be less than or equal to the
shutdown-threshold value.
Step 7
Switch(config-if)# exit
Returns to global configuration mode.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E