Reference Guide

822 | Service Provider Bridging
www.dell.com | support.dell.com
Figure 44-10. VLAN Stacking without L2PT
You might need to transport control traffic transparently through the intermediate network to the other
region. Layer 2 Protocol Tunneling enables BPDUs to traverse the intermediate network by identifying
frames with the Bridge Group Address, rewriting the destination MAC to a user-configured non-reserved
address, and forwarding the frames. Since the frames now use a unique MAC address, BPDUs are treated
as normal data frames by the switches in the intermediate network core. On egress edge of the intermediate
network, the MAC address rewritten to the original MAC address and forwarded to the opposing network
region (Figure 44-11).
Figure 44-11. VLAN Stacking with L2PT
FTOS Behavior: In FTOS version 9.0(1.3) and later, the L2PT MAC address is user-configurable, so you can
specify an address that non-Dell Networking systems can recognize and rewrite the address at egress edge.
I
N
T
E
R
N
E
T
S
E
R
V
R
I
C
E
P
R
O
V
I
D
E
R
w
/
ww
S
P
A
P
P
N
N
I
N
G
T
R
E
E
S
P
A
P
P
N
N
I
N
G
T
R
E
E
N
E
T
W
O
R
K
S
P
A
P
P
N
N
I
N
G
T
R
E
E
T
R
E
E
Building A
Building B
X
BPDU w/ destination
MAC address: 01-80-C2-00-00-00
no spanning-tree
no spanning-tree
I
N
T
E
R
N
E
T
S
E
R
V
R
I
C
E
P
R
O
V
I
D
E
R
w
/
w
S
P
A
P
P
N
N
I
N
G
T
R
E
E
R1-E-Series
R2
Non-Dell
System
S
P
A
P
P
N
N
I
N
G
T
R
E
E
N
E
T
W
O
R
K
S
P
A
P
P
N
N
I
N
G
T
R
E
E
T
R
E
E
R3
Non-Dell
System
Building A
Building B
BPDU w/ destination
MAC address: 01-80-C2-00-00-00
BPDU w/ destination
MAC address: 01-01-e8-00-00-00
BPDU w/ destination
MAC address: 01-80-C2-00-00-00
no spanning-tree
no spanning-tree