3Com 4200G 12-Port Configuration Manual page 154

140 C 20: MSTP C
HAPTER
BPDU Tunnel
Configuration
ONFIGURATION
As shown in Figure 38, the upper part is the operator's network, and the lower part is
the user network. The operator's network comprises packet ingress/egress devices,
and the user network has networks A and B. On the operator's network, configure
the arriving BPDU packets at the ingress to have MAC addresses in a special format,
and reconvert them back to their original formats at the egress. This is how
transparent transmission is implemented on the operator's network.
Figure 38 BPDU Tunnel network hierarchy
Packet ingress/egress Packet ingress/egress
device device
N etw ork A N etw ork A
Table 117 Configure the BPDU Tunnel function
Operation
Enter system view
Enable MSTP globally
Enable the BPDU
Tunnel function
globally
Enter Ethernet port
view
Disable MSTP for the
port
Enable the VLAN VPN
function for the
Ethernet port
The BPDU Tunnel function can only be enabled on devices with STP employed.
■
The BPDU Tunnel function can only be enabled on access ports.
■
To enable the BPDU Tunnel function, make sure the links between operator's
■
networks are trunk links.
As the VLAN-VPN function is unavailable on ports with 802.1x, GVRP, GMRP, STP,
■
or NTDP employed, the BPDU Tunnel function is not applicable to these ports.
O perator' s O perator' s
N etw ork N etw ork
U sers U sers
Command
system-view
stp enable
vlan-vpn tunnel
interface interface-type
interface-number
stp disable
vlan-vpn enable
N etw ork N etw ork
Packet ingress/egress Packet ingress/egress
device device
N etw ork N etw ork
N etw ork B N etw ork B
Description
-
-
Required
Make sure that you enter the Ethernet
port view of the port for which you
want to enable the BPDU Tunnel
function.
-
Required
By default, the VLAN VPN function is
disabled on all ports.