ECS4100 Series CLI Reference Guide-R07

Chapter 23 | VLAN Commands
Configuring L2PT Tunneling
– 579 –
◆ L2PT can be used to pass various types of protocol packets belonging to the
same customer transparently across a service provider’s network. In this way,
normally segregated network segments can be configured to function inside a
common protocol domain.
◆ L2PT encapsulates protocol packets entering ingress ports on the service
provider’s edge switch, replacing the destination MAC address with a
proprietary MAC address (for example, the spanning tree protocol uses 10-12-
CF-00-00-02), a reserved address for other specified protocol types (as defined
in IEEE 802.1ad – Provider Bridges), or a user-defined address. All intermediate
switches carrying this traffic across the service provider’s network treat these
encapsulated packets in the same way as normal data, forwarding them across
to the tunnel’s egress port. The egress port decapsulates these packets, restores
the proper protocol and MAC address information, and then floods them onto
the same VLANs at the customer’s remote site (via all of the appropriate tunnel
ports and access ports
14
connected to the same metro VLAN).
◆ The way in which L2PT processes packets is based on the following criteria – (1)
packet is received on a QinQ uplink port, (2) packet is received on a QinQ access
port, or (3) received packet is Cisco-compatible L2PT (i.e., as indicated by a
proprietary MAC address).
Processing protocol packets defined in IEEE 802.1ad – Provider Bridges
◆ When an IEEE 802.1ad protocol packet is received on an uplink port (i.e., an
802.1Q tunnel ingress port connecting the edge switch to the service provider
network)
■
with the destination address 01-80-C2-00-00-00,0B~0F (C-VLAN tag), it is
forwarded to all QinQ uplink ports and QinQ access ports in the same S-
VLAN for which L2PT is enabled for that protocol.
■
with the destination address 01-80-C2-00-00-01~0A (S-VLAN tag), it is
filtered, decapsulated, and processed locally by the switch if the protocol is
supported.
◆ When a protocol packet is received on an access port (i.e., an 802.1Q trunk port
connecting the edge switch to the local customer network)
■
with the destination address 01-80-C2-00-00-00,0B~0F (C-VLAN), and
■
L2PT is enabled on the port, the frame is forwarded to all QinQ uplink
ports and QinQ access ports on which L2PT is enabled for that protocol
in the same S-VLAN.
■
L2PT is disabled on the port, the frame is decapsulated and processed
locally by the switch if the protocol is supported.
14. Access ports in this context are 802.1Q trunk ports.