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Sun GigabitEthernet PCI Adapter 1.1 User’s Guide • March 1998
An Overview of VLANs
VLANs allow you to split your physical LAN into logical subparts, providing an
essential tool for increasing the efficiency and flexibility of your network.
VLANs are commonly used to separate groups of network users into manageable
broadcast domains, to create logical segmentation of workgroups, and to enforce
security policies among each logical segment. Each defined VLAN behaves as its
own separate network, with its traffic and broadcasts isolated from the others,
increasing the bandwidth efficiency within each logical group.
Although VLANs are commonly used to create individual broadcast domains and/
or separate IP subnets, it is sometimes useful for a server to have a presence on more
than one VLAN simultaneously. Sun GigabitEthernet adapters and SunSwitch
products support multiple VLANs on a per port or per interface basis, allowing very
flexible network configurations.
FIGURE 3-1
shows an example network that uses VLANs.
FIGURE 3-1
Example of Servers Supporting Multiple VLANs with Tagging Adapters
VLAN 1
VLAN 2
VLAN 3
Accounting
Server
(VLAN 3)
Main Server
Adapter
Gigabit/Tagged
(All VLANs)
Shared Media Segment
Engineering/
Software PC 5
Adapter
Gigabit/Tagged
(VLAN 1 & 2)
Accounting
PC 4
(VLAN 3)
Engineering
PC 3
(VLAN 1)
Software
PC 2
(VLAN 2)
Software
PC 1
(VLAN 2)
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8
10/100 Base - TX
Gigabit Ethernet