VLANs and Your Switch 63
■VLANs help to control traffic
With traditional networks, congestion can be caused by broadcast
traffic that is directed to all network devices w hether they require it or
not. VLANs increase the efficiency of your net work because each
VLAN can be set up to contain only those dev ices that need to
communicate with each other.
VLANs and Your Switch
Your Switch provides support for VLANs using the IEEE 802.1Q standard.
This standard allow s traffic from multiple V LANs to be carried acro ss one
physical link.
The IEEE 802.1Q standard allows each port on your Switch to be placed
in:
■Any one VLAN defined on the Switch.
■Several VLANs at the same time using 802.1Q tagging.
The standard requires that you define the following informati on about
each VLAN on your Switch before the Switch can use it to forward traffic:
■VLAN Name — This is a descriptive name for the VLAN (for example,
Marketing or Management).
■802.1Q VLAN ID — This is used to identify the VLAN if you use
802.1Q tagging across your network.
The Default VLAN A new or initialized Switch contains a single VLAN, the Default VLAN.
This VLAN has the following definition:
■VLAN Name — Default VLAN
■802.1Q VLAN ID — 1 (if tagging required)
All the ports are initially placed in this VLAN, and it is the only VLAN that
allows you to access the management softwa re of the Switch over the
network.
Creating New VLANs If you want to move a port from the Default VLAN to another VLAN, you
must first define information about the new V LAN on your Switch.