
15-14
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 15 Configuring 802.1Q and Layer 2 Protocol Tunneling
Configuring Layer 2 Protocol Tunneling
Use the no l2protocol-tunnel [point-to-point [pagp | lacp | udld]] interface configuration command to
disable point-to-point protocol tunneling for one of the Layer 2 protocols or for all three. Use the no
l2protocol-tunnel shutdown-threshold [point-to-point [pagp | lacp | udld]] and the no
l2protocol-tunnel drop-threshold [[point-to-point [pagp | lacp | udld]] commands to return the
shutdown and drop thresholds to the default settings.
Configuring the Customer Switch
After configuring the SP edge switch, begin in privileged EXEC mode and follow these steps to
configure a customer switch for Layer 2 protocol tunneling for EtherChannels:
Step 6
l2protocol-tunnel drop-threshold
[point-to-point [pagp | lacp | udld]]
value
(Optional) Configure 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
no cdp enable
Disable CDP on the interface.
Step 8
spanning-tree bpdufilter enable
Enable BPDU filtering on the interface.
Step 9
exit
Return to global configuration mode.
Step 10
errdisable recovery cause l2ptguard
(Optional) Configure the recovery mechanism from a Layer 2
maximum-rate error so that the interface is re-enabled and can try again.
Errdisable recovery is disabled by default; when enabled, the default time
interval is 300 seconds.
Step 11
l2protocol-tunnel cos value
(Optional) Configure 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 12
end
Return to privileged EXEC mode.
Step 13
show l2protocol
Display the Layer 2 tunnel ports on the switch, including the protocols
configured, the thresholds, and the counters.
Step 14
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter the interface configuration mode. This should be the customer switch
port.
Step 3
switchport trunk encapsulation
dot1q
Set the trunking encapsulation format to 802.1Q.
Step 4
switchport mode trunk
Enable trunking on the interface.
Step 5
udld enable
Enable UDLD in normal mode on the interface.