Cisco WS-C4003 Software Guide - Page 163
Configuring VLANs, Understanding How VLANs Work
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Configuring VLANs 10 C H A P T E R This chapter describes how to configure virtual LANs (VLANs) on the Catalyst enterprise LAN switches. Note For complete syntax and usage information for the commands used in this chapter, refer to the Command Reference-Catalyst 4000 Family, Catalyst 2948G, and Catalyst 2980G Switches. This chapter consists of these sections: • Understanding How VLANs Work, page 10-1 • VLAN Default Configuration, page 10-3 • VLAN Configuration Guidelines, page 10-3 • Configuring VLANs, page 10-3 • Configuring Private VLANs, page 10-7 Understanding How VLANs Work A VLAN is a group of end stations with a common set of requirements, independent of physical location. VLANs have the same attributes as a physical LAN but allow you to group end stations even if they are not located physically on the same LAN segment. VLANs allow you to group ports on a switch to limit unicast, multicast, and broadcast traffic flooding. Flooded traffic originating from a particular VLAN is only flooded out other ports belonging to that VLAN. Note Before you create VLANs, you must decide whether to use VTP or VMPS to maintain global VLAN configuration information for your network. For complete information on VTP, see Chapter 9, "Configuring VTP." For complete information on VMPS, see Chapter 12, "Configuring Dynamic Port VLAN Membership with VMPS." Figure 10-1 shows an example of VLANs segmented into logically defined networks. 78-12647-02 Software Configuration Guide-Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4 10-1
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