Users Guide

The TPID 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 congure TPID 0x9100, the system treats 0x8100 and untagged trac the same and maps both types to the default
VLAN, as shown by the frame originating from Building C. For the same trac types, if you congure TPID 0x8100, the system is able to
dierentiate between 0x8100 and untagged trac and maps each to the appropriate VLAN, as shown by the packet originating from
Building A.
Therefore, a mismatched TPID results in the port not dierentiating between tagged and untagged trac.
Figure 113. Single and Double-Tag TPID Match
Service Provider Bridging
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