D-Link DES-3216 manual Bridge Priority, Root Cost, Hello Time, Forward Delay Time, Max Age Time

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10/100 Auto Negotiation Switch User’s Guide

Bridge Priority

The Bridge Priority can be from 0 to 65535. Zero is the highest Bridge Priority. The higher the Bridge Priority the greater the chance that the DES-3216 will be selected as the Root Bridge. The DES-3216 with the highest Bridge Priority is the Root Bridge.

Root Cost

The Root Cost is the number of times a packet is regenerated before reaching its destination. A source sends a packet to the first device (switch or hub) on the network. When the packet reaches the next hub or switch and is sent out again, the Path Cost becomes two. Each switch and active hub regenerates the packet. To determine the Root Path Cost, count the number of times the packet is regenerated.

The switch with the lowest Path Cost is the Root Bridge. Make the Root Bridge the best switch on the network.

Hello Time

Is the interval between two transmissions of packets sent by the Root Bridge to tell all other switches that it is the Root Bridge. The Hello Time can be set manually, with a range in seconds from 1 to 10. If the Hello Time is set for the switch and the switch is not the Root Bridge then the Hello Time will not take effect until the switch becomes the Root Bridge.

Forward Delay Time

This is the time any port on the DES-3216 spends in the listening state while moving from the listening state to the forwarding state. It can be set from 4 to 30 seconds.

Use the following formula when setting the Hello Time and the Forward Delay Time:

2 x (Forward Delay minus 1 second) > Max Age

2 x (Hello Time plus 1 second) < Max Age

Max Age Time

Is the time a non-root bridge waits for a packet to be sent. At the end of the Max Age, if a packet has not been received from the Root Bridge, the DES-3216 will start sending its own packets and request permission to become the Root Bridge. If it turns out that the DES-3216 has the lowest Bridge Identifier it will become the Root Bridge.

The switch with the lowest Bridge Identifier is the Root Bridge. It is best to make the Root Bridge the best switch on the network to ensure the best network performance and reliability.

Root Bridge

Specifies the MAC address of the Root Bridge. The DES-3216 may or may not be the root bridge. The DES-3216 is the default root bridge.

Managing the DES-3216

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Contents DES-3216 10/100 Auto Negotiation Switch User’s Guide Link Limited Warranty Hardware North, Central, and South America FCC Warning Wichtige Sicherheitshinweise Table of Contents Page Page About This Guide AudienceOrganization Features IntroductionFront Panel Rear PanelManagement Methods Updating FirmwareLocal Console Management Telnet ManagementInstalling the DES-3216 Installation OptionsDesktop/ Shelf Installation Power On Rack InstallationConnecting the DES-3216 to the Network Cable SpecificationsCable Diagram Connecting the DES-3216 to the DES-5024 and Hubs PortsDES-3216 to DES-3216 Connection MDI-X PortLQN LEDsPower LED DES-3216 LED PanelLED Managing the DES-3216 Local Console ManagementTelnet ∙ Data bits ∙ Parity None ∙ Stop bits ∙ Flow Control None∙ Default User Name D-Link ∙ Default Password D-Link LogHelp Message Help MessagePanel Conventions SpacebarSystem Configuration Switch Port 1-8, 9-16 ConfigurationSpanning Tree Configuration Console ProgramSnmp Management Configuration Vlan Port ManagementTrunking Port Management System Configuration Menu System ResetFactory Reset to Default Config Values System InformationSoftware Update Boot Prom Firmware VersionSystem Information Menu Hardware RevisionLAN Default Gateway Software VersionMAC Address System DescriptionSystem Reset System ResetFactory Reset Factory ResetFactory Reset Confirmation System Rate Control Advantages of Store and ForwardDisadvantages of Store and Forward Advantages of Cut-Through Disadvantages of Cut-ThroughSoftware Update Menu Software UpdateSoftware Update Transfer File Transfer through Xmodem User Account Management User Account Change MenuCreate New User Password Confirm PasswordAccess Level User NameDelete Users StatusDelete Change Password Change PasswordOld Password New PasswordSwitch Port Configuration Switch Port Configuration Menu StatePhysical Port State PrioritySpanning Tree Configuration Spanning Tree Configuration MenuSTA Operation Levels Spanning Tree AlgorithmForward Delay Time Bridge PriorityRoot Cost Hello TimeRoot Port User Selective STA parametersSnmp Management Configuration Snmp Management Configuration MenuSnmp Manager Setting Access RightSnmp Community String Snmp Trap Manager Setting Authentication FailureCold Start Link Change EventPage Vlan Port Management Vlan Port Management MenuVlan Port Management menu Create New Vlan New Vlan NamePort # TrunkGroupDelete Vlan Menu Vlan NameModify Vlan Menu Virtual LAN NameTrunking Port Management Menu Trunking Port Management menuCreate New Trunking Port New Trunking Group NameName Delete Trunking Port Trunking PortModify Trunking Port Trunking Port NameTroubleshooting Problem SolutionPage Appendix a DES-3216 Technical Specifications Switch SpecificationsPort Specifications 10/100 Auto Negotiation Switch Users’ Guide General EMI 10/100 Auto Negotiation Switch Users’ Guide Performance Access Level IndexUser Name 32, 33