Reference Guide

Service Provider Bridging | 825
Figure 41-8. First-byte TPID Match on the E-Series ExaScale
Table 41-1 details the outcome of matched and mis-matched TPIDs in a VLAN-stacking network with the
E-Series.
VLAN Stacking with C-Series and S-Series
The default TPID for the outer VLAN tag is 0x9100. Beginning with FTOS version 8.2.1.0, both the
C-Series and S-Series allow you to configure both bytes of the 2-byte TPID. Previous versions allowed
you to configure the first byte only, and thus, the systems did not differentiate between TPIDs with a
common first byte. For example 0x8100 and any other TPID beginning with 0x81 were treated as the same
TPID, as shown in Figure 41-9. Versions 8.2.1.0 and later differentiate between 0x9100 and 0x91XY, as
shown in Figure 41-11.
Table 41-1. E-Series Behaviors for Mis-matched TPID
Network
Position
Incoming
Packet TPID
System
TPID Match Type TeraScale Behavior ExaScale Behavior
Core 0xUVWX 0xUVYZ 1st-byte match switch as 0xUVYZ drop
0xUVWZ 0xQRST mismatch drop drop
Egress Access
Point
0xUVWX 0xUVYZ 1st-byte match switch as 0xUVYZ drop
0x81WX 0x81YZ 1st-byte match switch as is (no
decapsulation)
drop
0xUVWZ 0xQRST mismatch drop drop
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 PURP
L
E
VL
AN
BLUE
VLAN RED
V
LAN R
E
D
VL
A
N
BLU
E
R2-E-Series ExaScale
TPID: 0x9100
R1-E-Series TeraScale
TPID: 0x9191
TPID 0x9191
X
Building C
Building D