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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 25 Configuring 802.1Q Tunneling, VLAN Mapping, and Layer 2 Protocol Tunneling
Configuring Layer 2 Protocol Tunneling
Use the no l2protocol-tunnel [cdp | stp | vtp] interface configuration command to disable protocol
tunneling for one of the Layer 2 protocols or for all three. Use the no l2protocol-tunnel
shutdown-threshold [cdp | stp | vtp] and the no l2protocol-tunnel drop-threshold [cdp | stp | vtp]
commands to return the shutdown and drop thresholds to the default settings.
This example shows how to configure Layer 2 protocol tunneling on an 802.1Q tunnel port for CDP, STP,
and VTP and how to verify the configuration:
Switch(config)# interface FastEthernet2/1
Switch(config-if)# switchport mode dot1q-tunnel
Switch(config-if)# l2protocol-tunnel cdp
Switch(config-if)# l2protocol-tunnel stp
Switch(config-if)# l2protocol-tunnel vtp
Switch(config-if)# l2protocol-tunnel shutdown-threshold 1500
Switch(config-if)# l2protocol-tunnel drop-threshold 1000
Switch(config-if)# exit
Switch(config)# l2protocol-tunnel cos 7
Switch(config)# end
Switch# show l2protocol
COS for Encapsulated Packets: 7
Port Protocol Shutdown Drop Encapsulation Decapsulation Drop
Threshold Threshold Counter Counter Counter
------- -------- --------- --------- ------------- ------------- -------------
Fa2/11 cdp 1500 1000 2288 2282 0
stp 1500 1000 116 13 0
vtp 1500 1000 3 67 0
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.
Step 8 Switch(config)# errdisable
recovery cause l2ptguard (Optional) Configures the recovery method from a Layer 2 maximum-rate
error so that the interface is reenabled and can try again. Errdisable recovery
is disabled by default; when enabled, the default time interval is 300
seconds.
Step 9 Switch(config)# l2protocol-tunnel
cos value (Optional) Configures the CoS value for all tunneled Layer 2 PDUs. The
range is 0 to 7; the default is the default CoS value for the interface. If none
is configured, the default is 5.
Step 10 Switch(config)# end Returns to privileged EXEC mode.
Step 11 Switch# show l2protocol Displays the Layer 2 tunnel ports on the switch, including the protocols
configured, the thresholds, and the counters.
Step 12 Switch# copy running-config
startup-config (Optional) Saves your entries in the configuration file.
Command Purpose