Allied Telesis AT-2931SX manual Component Description, Vlan #1

Chapter 5: Key Protocols and Interfaces

Figure 14 on page 69 shows an example network that uses VLANs. In this example network, the physical LAN consists of a switch, two servers, and five clients. The LAN is logically organized into three different VLANs, each representing a different IP subnet. The features of this network are described in Table 8.

	Table 8. Example VLAN Network Topology
Component		Description
VLAN #1		An IP subnet consisting of the Main Server, PC #3,
		and PC #5. This subnet represents an engineering
		group.
VLAN #2		Includes the Main Server, PCs #1 and #2 via shared
		media segment, and PC #5. This VLAN is a software
		development group.
VLAN #3		Includes the Main Server, the Accounting Server and
		PC #4. This VLAN is an accounting group.
Main Server		A high-use server that needs to be accessed from all
		of the VLANs and IP subnets. The Main Server has an
		AT-2931SX adapter installed. All three IP subnets are
		accessed via the single physical adapter interface.
		The server is attached to one of the switch ports,
		which is configured for VLANs #1, #2, and #3. Both
		the adapter and the connected switch port have
		tagging turned on. Because of the tagging VLAN
		capabilities of both devices, the server is able to
		communicate on all three IP subnets in this network,
		but continues to maintain broadcast separation
		between all of them.
Accounting		Available to VLAN #3 only. The Accounting Server is
Server		isolated from all traffic on VLANs #1 and #2. The
		switch port connected to the server has tagging
		turned off.
PCs #1 and		Attached to a shared media hub that is then
#2		connected to the switch. PCs #1 and #2 belong to
		VLAN #2 only, and are logically in the same IP subnet
		as the Main Server and PC #5. The switch port
		connected to this segment has tagging turned off.
PC #3		A member of VLAN #1, PC #3 can communicate only
		with the Main Server and PC #5. Tagging is not
		enabled on PC #3’s switch port.
PC #4		A member of VLAN #3, PC #4 can only communicate
		with the servers. Tagging is not enabled on PC #4’s
		switch port.

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