IBM ATM OC-3c - Manual (Page 29)

3
V
IRTUAL
LAN C
ONCEPTS
This chapter provides a brief overview of
Virtual LAN (VLAN) concepts, and describes how to
extend VLANs into the ATM network.
This user guide does not describe how to create or
configure VLANs. VLAN configuration is described in
the user guide that accompanies your Switch.
What is a Virtual LAN (VLAN)?
A Virtual LAN (VLAN) is a flexible, location and topology
independent group of end-stations communicating as
if they are on a common physical LAN.
You can create VLANs that closely correspond to how
your network and business functions. For example,
marketing personnel in different physical locations
could be part of one VLAN and finance personnel
could be in another VLAN.
VLANs provide the following benefits:
■ VLANs make moves and changes simple.
■ As each VLAN is a common broadcast domain, you
can erect firewalls against broadcast storms.
■ VLANs improve security.
For a full description of VLAN functionality, refer to
the user guide that accompanies your Switch.
Creating Inter-switch VLANs
You can create inter-switch VLANs using Virtual LAN
Trunks (VLTs) on Fast Ethernet connections, as shown
in Figure 3-1.
Figure 3-1 Inter-switch VLANs