Virtual Networks; Virtual Lan Basics - 3Com CoreBuilder 7000 Operation Manual

8

Virtual LAN Basics

Advantages
V N
IRTUAL
This chapter discusses virtual networks and their implementation in the
CoreBuilder ® 7000 family ATM switch.
The following topics are discussed:


Virtual LAN Basics


VLANs in the CoreBuilder 7000


Virtual LANs for Three Workgroups
Just as an Ethernet LAN enables a group of stations to communicate
efficiently on a common physical bus, new ATM networking technology
makes it possible for stations on different LANs to communicate with
almost the same efficiency—even when separated by great distances.
Network managers can now group remote stations that need to
communicate frequently into a common high-bandwidth broadcast
domain called a Virtual LAN. For example, marketing department
personnel who work in different physical locations could be formed into
one Virtual LAN and engineering department personnel into another. The
term Virtual LAN is used because communicating stations continue to
transmit and receive as though they were on the same physical Ethernet
LAN. In this manual, the abbreviation VLAN is used for a Virtual LAN.
In practice, it is not the individual LAN stations that are formed into
VLANs but rather it is the physical Ethernet LANs, called Ethernet
segments, that are grouped into VLANs. Thus, all stations on an Ethernet
segment will be on the same VLAN. Also, since a Ethernet segment is
connected to the network through an Ethernet port in a edge device, the
Ethernet port itself is sometimes referred to as a member of the VLAN.
A Virtual LAN, as opposed to an Ethernet LAN, has the great advantage
of being very easy to manage from a central location. 3Com's Transcend
Manager application is the tool of choice for this job. Stations are added
ETWORKS