Edge-Core AS5700-54X, Справочное руководство CLI, Страница: 494 / 1116

Chapter 18
| VLAN Commands
Configuring L2CP Tunneling
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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 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
9
connected to the same metro VLAN).
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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.
■
with destination address 01-80-C2-00-00-01~0A (S-VLAN), the frame is
filtered, decapsulated, and processed locally by the switch if the protocol is
supported.
Processing Cisco-compatible protocol packets
◆
When a Cisco-compatible L2PT packet is received on an uplink port, and
■ recognized as a CDP/VTP/STP/PVST+ protocol packet (where STP means
STP/RSTP/MSTP), it is forwarded to the following ports in the same S-VLAN:
9. Access ports in this context are 802.1Q trunk ports.