LSI Logic Corporation
Page 36 of 56
In the example network shown in Figure 6, 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 the following table.
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 VLANs
and IP subnets. The Main Server has an ITI5100G adapter
installed. All three IP subnets are accessed via the single
physical adapter interface. The server is attached to an Alteon
WebSystems switch Gigabit Ethernet port, 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
Server
Available to VLAN #3 only. The Accounting Server is
isolated from all traffic on VLANs #1 and #2. The switch port
connected to the server has tagging turned off.
PCs #1 and #2
Attached to a shared media hub that is then 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.
PC #5
A member of both VLANs #1 and #2, PC #5 has an ITI5100G
adapter installed. It is connected to switch port #10. Both the
adapter and the switch port are configured for VLANs #1 and
#2 and have tagging enabled.
Table 9: Example VLAN Network Topology