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CHAPTER 5
Configuring VLANs
This chapter explains VLANs in detail and provides configuration instructions and
examples.
■VLANs: Virtual Local AreaNetworks (VLANs) are commonly used to split up
groups of network users into manageable broadcast domains, to create logical
segmentation of workgroups, and to enforce security policies among each logical
segment. 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-awareadapter 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 will take effect. If you make changes and do not
reboot, you may experience configuration problems.

An Overview of VLANs

VLANs allow 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.