ES-3124 User’s Guide
164 Chapter 21 VLAN Stacking
Figure 68 VLAN Stacking Example
21.2 VLAN Stacking Port Roles
Each port can have three VLAN stacking “roles”, Normal, Access Port and Tunnel (the latter
is for Gigabit ports only).
• Select Normal for “regular” (non-VLAN stacking) IEEE 802.1Q frame switching.
• Select Access Port for ingress ports on the service provider's edge devices (1 and 2 in the
VLAN stacking example figure). The incoming frame is treated as "untagged", so a
second VLAN tag (outer VLAN tag) can be added.
Note: Static VLAN Tx Tagging MUST be disabled on a port where you choose
Normal or Access Port.
• Select Tunnel Port (available for Gigabit ports only) for egress ports at the edge of the
service provider's network. All VLANs belonging to a customer can be aggregated into a
single service provider's VLAN (using the outer VLAN tag defined by SP VID).
Note: Static VLAN Tx Tagging MUST be enabled on a port where you choose
Tunnel Port.
21.3 VLAN Tag Format
A VLAN tag (service provider VLAN stacking or customer IEEE 802.1Q) consists of the
following three fields.
Table 48 VLAN Tag Format
Type Priority VID
