User manual

Page 22-1
22 Managing AutoTracker
VLANs
In a large, flat, switched network, broadcast traffic can overload a network based primarily on
port-based Groups. Through the use of AutoTracker VLANs, you can control broadcast traffic
such that it is forwarded only to those VLANs where it needs to be sent.
VLANs are created within a Group to subdivide network traffic based on specific criteria. The
criteria you use to define a VLAN are called AutoTracker policies. AutoTracker policies can be
defined by port, MAC address, protocol, network address, a user-defined policy, or a multi-
cast policy. You can also define multiple policies—also referred to as “rules”—for a VLAN if
you wish. A port or device is included in a VLAN if it matches any one VLAN rule. For exam-
ple, you can define rules based on MAC address and rules based on protocol in the same
VLAN.
A Group defines a physical space within the network—a set of ports. The policies that you
define for
VLAN membership are applied to all traffic on those ports, but not to traffic on
ports outside the Group.
You can create two types of policy-based
VLANs: AutoTracker VLANs and multicast VLANs.
You can create up to 31 AutoTracker VLANs and up to 32 multicast VLANs in any one Group.
AutoTracker VLANs and multicast VLANs operate independently of one another: the policies
you establish for AutoTracker VLANs neither conflict nor interfere with the policies you estab-
lish for multicast VLANs, even when those policies involve the same ports or MAC addresses.
This chapter provides an overview of AutoTracker
VLANs and multicast VLANs as well as
instructions for managing and monitoring each type of VLAN. Instructions for configuring
AutoTracker policies can be found in Chapter 20, “Configuring Group and VLAN Policies.”