User's Guide Gigabit Ethernet Host Adapters ITIpci 5100G/GF

LSI Logic Corporation Page 35 of 56
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.
Overview
Each defined VLAN behaves as its own separate network, with its traffic and
broadcasts isolated from the other VLANs to increase bandwidth efficiency
within each logical group. One example of how VLANs can be used to
segment a LAN is when isolating different types of network traffic. If you
wanted to utilize Jumbo Frames on a portion of your LAN, you could
configure one VLAN for devices that support Jumbo Frames, and a separate
VLAN for devices supporting only standard frames. By implementing
VLANs, you could segregate the different frame types from each other
without reorganizing your LAN into separate physical subnets.
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. Alteon WebSystems
switches and ITI5100G/GF adapters support multiple VLANs on a per-port
or per-interface basis, allowing very flexible network configurations.
See Figure 6 for an example of servers supporting multiple VLANs with
Tagging.
Figure 6: Servers Supporting Multiple VLANs
VLAN #1
VLAN #2
VLAN #3
Accounting Server
(VLAN #3)
Shared
Media Se
g
ment
Main Server
(All VLANs)
ITI5100G Gigabit
VLAN Tagged
PC #5
Engineering/Software
(VLAN #1 & #2)
ITI5100G Gigabit
VLAN Ta
gg
e
d
PC #4
Accounting
(VLAN #3)
PC #3
Engineering
(VLAN #1)
PC #2
Software Dept.
(VLAN #2)
PC #1
Software Dept.
(VLAN #2)