Allied Telesis AT-S79 manual Port assignments for the VLANs are as follows

AT-S79 Management Software User’s Guide

The port assignments for the VLANs are as follows:

	Sales VLAN (VID 2)		Engineering VLAN		Production VLAN
			(VID 3)		(VID 4)
	Untagged	Tagged	Untagged	Tagged	Untagged	Tagged
	Ports	Ports	Ports	Ports	Ports	Ports
AT-GS950/	1, 3, 5, 6	2, 10	9, 11 to 13	2, 10	17, 19 to 21	2
24 Switch	(PVID 2)		(PVID 3)		(PVID 4)
(top)
AT-GS950/	2, 4, 6, 8	9	16, 18, 20,	9	none	none
24 Switch	(PVID 2)		22
(bottom)			(PVID 3)

This example is nearly identical to the “Port-based Example 2” on page 78, but tagged ports have been added to simplify network implementation and management.

One of the tagged ports is port 2 on the top switch. This port has been made a tagged member of the three VLANs. It is connected to an IEEE 802.1Q-compliant server, meaning the server can handle frames from multiple VLANs. Now all three VLANs can access the server without going through a router or other interconnection device.

It is important to note that even though the server is accepting frames from and transmitting frames to more than one VLAN, data separation and security remain.

Two other tagged ports are used to simplify network design in the example. They are port 10 on the top switch and port 9 on the lower switch. These ports have been made tagged members of the Sales and Engineering VLANs so that they can carry traffic from both VLANs, simultaneously. These ports provide a common connection that enables different parts of the same VLAN to communicate with each other while maintaining data separation between VLANs.

In comparison, the Sales and Engineering VLANs in the “Port-based Example 2” on page 78 each had to have its own individual network link between the switches to connect the different parts of the VLANs. But with tagged ports, you can use one data link to carry data traffic from several VLANs, while still maintaining data separation and security. The tagged frames, when received by the switch, are delivered only to those ports that belong to the VLAN from which the tagged frames originated.

Section I: Using the Menus Interface 83