ZyXEL Communications 4528F User Manual

 Chapter 9 VLAN

XGS-4526/4528F/4728F User’s Guide

Enable VLAN Trunking on a port to allow frames belonging to unknown VLAN 
groups to pass through that port. This is useful if you want to set up VLAN groups 
on end devices without having to configure the same VLAN groups on 
intermediary devices.

The following figure describes VLAN Trunking. Suppose you want to create VLAN 
groups 1 and 2 (V1 and V2) on devices A and B. Without VLAN Trunking, you 
must configure VLAN groups 1 and 2 on all intermediary switches C, D and E; 
otherwise they will drop frames with unknown VLAN group tags. However, with 
VLAN Trunking enabled on a port(s) in each intermediary switch you only need 
to create VLAN groups in the end devices (A and B). C, D and E automatically 

VLAN 
Administrative 
Control 

Registration Fixed  Fixed registration ports are permanent VLAN 

members.

Registration 
Forbidden 

Ports with registration forbidden are forbidden to 
join the specified VLAN.

Normal 
Registration

Ports dynamically join a VLAN using GVRP.

VLAN Tag Control  Tagged 

Ports belonging to the specified VLAN tag all 
outgoing frames transmitted.

Untagged 

Ports belonging to the specified VLAN don't tag all 
outgoing frames transmitted.

VLAN Port

Port VID 

This is the VLAN ID assigned to untagged frames 
that this port received.

Acceptable Frame 
Type 

You may choose to accept both tagged and 
untagged incoming frames, just tagged incoming 
frames or just untagged incoming frames on a 
port.

Ingress filtering 

If set, the Switch discards incoming frames for 
VLANs that do not have this port as a member.

Table 15   IEEE 802.1Q VLAN Terminology  (continued)