ZyXEL Communications 4528F User Manual

 Chapter 23 VLAN Stacking

XGS-4526/4528F/4728F User’s Guide

The following table describes the labels in this screen.

Port-based Q-in-Q lets the Switch treat all frames received on the same port as 
the same VLAN flows and add the same outer VLAN tag to them, even they have 
different customer VLAN IDs.

Table 59   Advanced Application > VLAN Stacking

Active

Select this checkbox to enable VLAN stacking on the Switch. 

Port

The port number identifies the port you are configuring.

*

Settings in this row apply to all ports.

Use this row only if you want to make some settings the same for all ports. Use 
this row first to set the common settings and then make adjustments on a port-
by-port basis. 

Note: Changes in this row are copied to all the ports as soon as you make 

them.

Role

Select Normal to have the Switch ignore frames received (or transmitted) on 
this port with VLAN stacking tags. Anything you configure in SPVID and 
Priority of the Port-based QinQ or the Selective QinQ screen are ignored.

Select Access Port to have the Switch add the SP TPID tag to all incoming 
frames received on this port. Select Access Port for ingress ports at the edge 
of the service provider's network.

Select Tunnel Port (available for Gigabit ports only) for egress ports at the 
edge of the service provider's network. Select Tunnel Port to have the Switch 
add the Tunnel TPID tag to all outgoing frames sent on this port.

In order to support VLAN stacking on a port, the port must be able to allow 
frames of 1526 Bytes (1522 Bytes + 4 Bytes for the second tag) to pass 
through it.

Tunnel 
TPID

TPID is a standard Ethernet type code identifying the frame and indicates 
whether the frame carries IEEE 802.1Q tag information. Enter a four-digit 
hexadecimal number from 0000 to FFFF that the Switch adds in the outer VLAN 
tag of the frames sent on the tunnel port(s). The Switch also uses this to check 
if the received frames are double-tagged.

The value of this field is 0x8100 as defined in IEEE 802.1Q. If the Switch needs 
to communicate with other vendors’ devices, they should use the same TPID.

Note: You can define up to four different tunnel TPIDs (including 8100) in 

this screen at a time.

Apply

Click Apply to save your changes to the Switch’s run-time memory. The Switch 
loses these changes if it is turned off or loses power, so use the Save link on 
the top navigation panel to save your changes to the non-volatile memory 
when you are done configuring.

Cancel

Click Cancel to begin configuring this screen afresh.