NETGEAR GS748TS-100NAS, GS748TNA user manual Appendix B Virtual Local Area Networks VLANs

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Appendix B

Virtual Local Area Networks (VLANs)

A Local Area Network (LAN) can generally be defined as a broadcast domain. Hubs, bridges or switches in the same physical segment or segments connect all end node devices. End nodes can communicate with each other without the need for a router. Routers connect LANs together, routing the traffic to the appropriate port.

A virtual LAN (VLAN) is a local-area network with a definition that maps workstations on some other basis than geographic location (for example, by department, type of user, or primary application). To communicate between VLANs, traffic must go through a router, just as if they were on two separate LANs.

A VLAN is a group of PCs, servers and other network resources that behave as if they were connected to a single, network segment—even though they may not be. For example, all marketing personnel may be spread throughout a building. Yet if they are all assigned to a single VLAN, they can share resources and bandwidth as if they were connected to the same segment. The resources of other departments can be invisible to the marketing VLAN members, accessible to all, or accessible only to specified individuals, depending on how the IT manager has set up the VLANs.

The Advantages of VLANs:

Easy to do network segmentation: Users that communicate most frequently with each other can be grouped into common VLANs, regardless of physical location. Each group's traffic is largely contained within the VLAN, reducing extraneous traffic and improving the efficiency of the whole network.

Easy to manage: The addition of nodes, as well as moves and other changes, can be dealt with quickly and conveniently from a management interface rather than from the wiring closet.

Increased performance: VLANs free up bandwidth by limiting node-to-node and broadcast traffic throughout the network.

Enhanced network security: VLANs create virtual boundaries that can only be crossed through a router. So standard, router-based security measures can be used to restrict access to each

VLAN

Virtual Local Area Networks (VLANs)

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v2.0, April 2007

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Contents NETGEAR, Inc Statement of Conditions TrademarksCertificate of the Manufacturer/Importer Bestätigung des Herstellers/ImporteursEurope EU Declaration of Conformity Regulatory Compliance InformationFCC Information to User FCC Requirements for Operation in the United StatesGS748T Smart Switch Product and Publication Details Contents Appendix a Specifications and Default Values Appendix C Network Cabling V2.0, April About This Manual How to Use This BookWho Should Use this Book Bold Conventions, Formats and ScopeHtml Manual Navigation How to Print this ManualDocument Date Version Description Part Number Revision HistorySwitch Management Interface Chapter Switch Management OverviewSystem Requirements Switch Management MethodsNetwork with Dhcp server Getting Started-Smart Wizard DiscoveryNetwork without Dhcp Server Manually Assigning Network Parameters V2.0, April Password Change Web AccessAdditional Utilities Firmware Upgrade Exit V2.0, April Starting Web Management Chapter Basic Web ManagementNetgear Home Page and Switch Status V2.0, April Description of Switch Status Parameters V2.0, April System Functions Firmware Menu Managing System Files-Backup and RestoreTo restore saved settings Factory ResetTo back up files Logout Resetting the SystemV2.0, April Using the Switch Configuration Utility Chapter Configuring the SwitchPort Configuration Viewing Packet Statistics V2.0, April Port-based QoS Regulating Traffic Rates using Quality of Service SettingsIeee 802.1p-based QoS Differentiated Services Code Point DSCP-based QoS Vlan Adding and Configuring Ieee 802.1Q Vlan Groups Reconfiguring an Ieee 802.1Q Vlan Group Reconfiguring a Port-based Vlan Adding and Configuring Port-based VLANsSelecting a Management Vlan Creating Port Trunks to Increase Link BandwidthSetting up Port Trunks Removing Port Trunks Using a Sniffer Port to Monitor TrafficControlling Per-port Packet Throughput Jumbo Frame SupportStorm Control Dropping Traffic that is Flooding a Port Using Spanning Tree Protocol to Prevent Path LoopsV2.0, April V2.0, April Enabling Switch Management using Snmp To Add a MAC Address Controlling Switch Access by MAC Address and Vlan IDFiltering Unknown Multicast Packets Using Igmp Snooping to Route Packets Based on ContentTo Remove a MAC Address from the Table Setting Up Static Multicast Groups V2.0, April GS748T Smart Switch Specifications Appendix a Specifications and Default ValuesTable A-3. Port Characteristics GS748T Smart Switch Features and DefaultsTable A-8. Other Features Smart Wizard Enabled Statistics Per port Appendix B Virtual Local Area Networks VLANs Example Ieee 802.1Q VLANsPort-based VLANs Port-based Vlan Example ConfigurationResults of this Configuration Fast Ethernet Cable Guidelines Appendix C Network CablingCategory 5 Cable Twisted Pair Cables Category 5 Cable SpecificationsFigure C-1Straight-Through Twisted-Pair Cable Patch Panels and CablesCabling Using 1000BASE-T Gigabit Ethernet over Category 5 CableLength Near End Cross Talk NextReturn Loss Patch Cables RJ-45 Plug and RJ-45 ConnectorsConclusion V2.0, April