Dell Force10 C150 Configuration Manual page 957

Figure 46-6. TPID Match and First-byte Match on the E-Series TeraScale
R1-E-Series TeraScale
TPID: 0x9191
Building C
TPID 0x8100 on E-Series TeraScale Systems
E-Series TeraScale treats TPID 0x8100 as a normal VLAN even when on the outer tag. E-Series TeraScale
makes forwarding decisions based strictly on the protocol type, without regard for whether the port is an
access port. Therefore, when the outer tag has TPID 0x8100, the system does not remove it from frames
egressing an access port. Still, although the frames cannot be decapsulated, the system is able to switch
them. In Figure
switched towards Building B, but is not decapsulated on egress at R2 because its TPID is 0x8181.
FTOS Behavior: The E-Series ExaScale and TeraScale forward frames with TPID 0x8100 even when
its own TPID is not 0x8100. This behavior is required to service ARP and PVST packets, which use
TPID 0x8100.
TPID 0x9191
R2-E-Series TeraScale
TPID: 0x9100
R4-Non-Force10 System
TPID: 0x9100
46-7, the frame originating from Building A is double tagged on egress at R4 and is
Building D
R3-E-Series TeraScale
TPID: 0x9100
PCP
TPID CFI
(0x9100) (0) (VLAN Purple)
R4
Building A
Building B
PCP
VID TPID CFI
(0x8100) (0) (VLAN Red)
PCP
TPID CFI
(0x8100) (0) (VLAN Red)
Service Provider Bridging | 957
VID
VID