VLANs ease the movement of devices on networks | 3Com 3 specification

62CHAPTER 8: SETTING UP VIRTUAL LANS

Figure 16 A network setup showing three VLANs

Benefits of VLANs The main benefit of VLANs is that they provide a network segmentation system that is far more flexible than any traditional network. Using VLANs also provides you with three other benefits:

■VLANs ease the movement of devices on networks

With traditional networks, network administrators spend much of their time dealing with moves and changes. If users move to a different subnetwork, the addresses of each endstation must be updated manually.

With a VLAN setup, if an endstation in VLAN Marketing for example is moved to a port in another part of the network, and retains its original subnet membership, you only need to specify that the new port is in VLAN Marketing. You do not need to carry out any re-cabling.

■VLANs provide extra security

Devices within each VLAN can only communicate with other devices in the same VLAN. If a device in VLAN Marketing needs to communicate with devices in VLAN Finance, the traffic must pass through a routing device or Layer 3 switch.

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3Com 3 manual VLANs ease the movement of devices on networks, VLANs provide extra security

Contents

SuperStack 3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents Using Multicast Filtering Status Monitoring and Statistics IP Addressing About this Guide Conventions List conventions that are used throughout this guide Comments RelatedDocumentation Pddtechpubscomments@3com.com Product Registration Switch Features Page Management What isSwitch Features Software? Switch Features Overview Duplex Ports operating at 1000 Mbps only support full duplex modeFor more information about multicast filtering, see Using Flow Control For more information about STP and RSTP, see Using Resilience Features Event Notification Quality of ServiceFor more information about Quality of Service, see Using For more information about VLANs, see Setting Up Virtual Port Features Ports operating at 1000 Mbps support full duplex mode only Port Features Switch units connected using an aggregated link Aggregated Links Traffic Distribution and Link Failure on Aggregated Links 2 Gbps aggregated link between two Switch units Optimizing Bandwidth Using Multicast Filtering Relevant multicast group Using Multicast Filtering Query Mode Query modeSnooping Mode Igmp multicast filtering works as follows Igmp v2 protocolThat support IP Enabling Igmp Multicast Learning Igmp Multicast Filtering Using Multicast Filtering Network Spanning TreeProtocol STP Ieee 802.1w standard What is STP? Traffic flowing through Bridge B Port Speed Link Type Path Cost 802.1D-1998 802.1w Using Resilience Features Port costs in a network Configuration 3 Redundancy for Cabling Error Configuration 1 Redundancy for Backbone LinkConfiguration 2 Redundancy through Meshed Backbone STP configurations Network with Default BehaviorUsing STP on a Multiple VLANs Configuration that separates VLANs Using Resilience Features Database? What is the SwitchHow Switch Database Entries Switch Database Entry States Databases entries can have three states Available What is TrafficPrioritization? Converged network applications Used by organizations with a 802.1D Priority Levels How Traffic Prioritization Works Your Switch Traffic Prioritization How traffic is processed to provide Quality of Service Configuring traffic prioritization for QoS on a Switch Using Traffic Prioritization That allows you to monitor the traffic of LANs or VLANs What is RMON?Network efficiency and reduce the load on your network It improves your efficiency AlarmsEvents Switch Rmon Low Threshold Statistic High Threshold Recovery Period Low Threshold Statistic High Threshold Recovery Status Monitoring and Statistics Hardware Status Monitoring Example device summary web Setting UP Virtual Lans VLANs ease the movement of devices on networks VLANs provide extra security VLANs help to control traffic Membership Creating an Ieee 802.1Q Tagged Link Two Vlans connected via a router Configure the VLANs ConfigurationUsing Untagged Examples Add ports to the VLANs Configure the VLANs on SwitchAdd endstation ports on Switch 1 to the VLANs Add port 11 on Switch 2 to the VLANs Add port 12 on Switch 1 to the VLANsAdd endstation ports on Switch 2 to the VLANs Check the Vlan membership for both switches Configuration Information How Your SwitchObtains IP How Automatic IP How Automatic IP Configuration Works Considerations Automatic IP configuration featureThat a Switch may change its IP address whilst in use Glossary Configuration RulesIP Addressing IndexPage Configuration Rules Configuration Rules for Gigabit Ethernet Fast Ethernet configuration rules Configuration Rules for Fast Ethernet Appendix a Configuration Rules Network This chapter contains the following sections Family and 4900 family can be used in your network Segments are connected to the Switch which is positionedSimple Network Example Dual Speed Hub Switch Resilience of Your Advanced NetworkImproving Network Therefore the overall network performance EnhancingPerformance IP Addresses Simple Overview Obtaining a Registered IP Address IP Address Network Portion Dotted Decimal NotationDecimal value of an octet whose bits are all 1s is Subnet mask Subnet Mask Numbering Extending the Network Prefix Or leave the field blank Glossary Glossary Ethernet address EndstationEthernet Fast Ethernet Hub GatewayHalf duplex Ieee 802.1D Line speed See baud Glossary Rstp See Rapid Spanning Tree Protocol STP See Spanning Tree Protocol STP Page Glossary Index Numbers Igmp multicast filtering 30 Internet Addresses 85 InterNIC Sub-networks. See subnets Switch Database