ZyXEL Communications GS-4012F, Руководство пользователя

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GS-4012F User’s Guide
136 Chapter 21 VLAN Stacking
Figure 58 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 (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.
21.3 VLAN Tag Format
A VLAN tag (service provider VLAN stacking or customer IEEE 802.1Q) consists of the
following three fields.
Table 42 VLAN Tag Format
Type Priority VID