Dell Force10 S4810P - Page 922

922 | Service Provider Bridging
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You can configure the first eight bits of the TPID using the command vlan-stack protocol-type.
The TPID on the C-Series and S-Series systems is global. Ingress frames that do not match the system
TPID are treated as untagged. This rule applies for both the outer tag TPID of a double-tagged frame and
the TPID of a single-tagged frame.
For example, if you configure TPID 0x9100, then the system treats 0x8100 and untagged traffic the same
and maps both types to the default VLAN, as shown by the frame originating from Building C in
Figure 44-11. For the same traffic types, if you configure TPID 0x8100, then the system is able to
differentiate between 0x8100 and untagged traffic and maps each to the appropriate VLAN, as shown by
the packet originating from Building A in Figure 44-11.
Therefore, a mismatched TPID results in the port not differentiating between tagged and untagged traffic.
Figure 44-9. Single and Double-tag TPID Match on the C-Series and S-Series
I
N
T
E
R
N
E
T
S
E
R
V
I
C
E
P
R
O
V
I
D
E
R
VLAN GREEN, VLAN PURPLE
VLAN GREEN
VLAN PURPLE
VLAN BLUE
VLAN RED
VLAN RED
VLAN BLUE
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Red)
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Red)
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Purple)
Building A
Building B
R2-C-Series
TPID: 0x8100
R1-C-Series
TPID: 0x8100
R4-Non-Force10 System
TPID: 0x8100
TPID 0x8100
R3-C-Series
TPID: 0x8100
Building D
Building C