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CHAPTER 5
Configuring VLANs
This chapter explains virtual local area networks (VLANs) in detail and provides
configuration instructions and examples. It contains the following sections:
■“Overview of VLANs” on page 57
■“Configuring VLANs” on page 59
Withmultiple VLANs on an adapter,a server with a single adapter can have a
logical presence on multiple IP subnets. By default, 128 VLANs can be defined for
each VLAN-aware adapter on your server.However, this number can be increased
by changing the system parameters.
If your network does not require multiple VLANs, you can use the default
configuration, in which case no further configuration is necessary.
Note – If you change any of the VLAN configuration parameters, you must reboot
the system before the changes take effect. If you make changes and do not reboot,
you might experience configuration problems.

Overview of VLANs

VLANs enable you to split your physical LAN into logical subparts, providing an
essential tool for increasing the efficiency and flexibilityof 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 fromthe others,
increasing the bandwidth efficiency within each logical group.