Reference Guide

846 | Service Provider Bridging
www.dell.com | support.dell.com
Figure 43-279. TPID Mismatch and 0x8100 Match on the E-Series TeraScale
VLAN Stacking with E-Series ExaScale Systems
E-Series ExaScale, beginning with FTOS version 8.2.1.0, allows you to configure both bytes of the 2-byte
TPID. TeraScale systems allow you to configure the first byte only and thus, the system did not
differentiate between TPIDs with a common first byte. For example 0x9100 and 0x91A8 were treated as
the same TPID. In Figure 43-278, R2 forwards the frame with TPID 0x9191 which originated from
Building C. In contrast, R2 drops the frame with TPID 0x9191 originating from Building C in
Figure 43-280 because the frames TPID does not match both bytes of its own TPID.
FTOS Behavior: The E-Series ExaScale and TeraScale forwards 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.
I
N
T
E
R
N
E
T
S
E
R
V
I
C
E
P
R
O
V
I
D
E
R
VL
AN GREE
N
, VLAN PURP
L
E
VLAN G
REEN
V
LAN
PU
RP
L
E
VL
AN
BLUE
VLAN RED
V
LAN R
E
D
V
L
A
N
BLU
E
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Red)
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Red)
TPID
(0x8100)
PCP
CFI
(0)
VID
(VLAN Purple)
R2-E-Series TeraScale
Building A
Building B
TPID: 0x8181
R3-E-Series TeraScale
TPID: 0x8181
R4-Non-Force10 System
TPID: 0x8100
R1-E-Series TeraScale
TPID: 0x9100
TPID 0x8100
X
X
TPID 0x9100
Building C
Building D