3Com 2000 TR manual Bridge Parameters, Spanning Tree

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The following fields are shown on the screen:

Unit ID—Identifies the currently selected Switch unit.

Port ID—Displays the current module type. It should read TIF.

Admin. State—This field allows you to *Enable* or *Disable* the TR-in-FE port.

Internal Priority—This field allows you to distribute the available bandwidth among the ports. *High* pri- ority ports are given priority access to internal resources, taking priority over *Normal* priority ports.

Full Duplex—The TR-in-FE Module works with either a Full Duplex or Half Duplex mode of operation. The Full Duplex field allows you to *Enable* or *Disable* Full Duplex mode. Disabling Full Duplex automatically puts the TR-in-FE Module in Half Duplex mode.

Max Packet Size—This field allows you two choices for setting the maximum packet size.

1518—Use this value in traditional Fast Ethernet environments.

4544—Use this value for larger packets when configured with a SuperStack II Switch 3000.

Jamming Mode—This field allows you to restrict the amount of packet loss allowable when configured with conventional switches. Jamming provides a vari- able parameter for determining the number of colli- sions. This feature is most helpful in networks using lots of repeaters. Choose from J6 through J13 where

Setting Up a Module

5-3

J6 indicates the least amount of effort by the port to back off collisions. A value of J13 indicates more effort on the port. This feature is reserved for quali- fied and knowledgeable network managers.

VLAN Enable Mask—This field allows you to restrict or allow for membership in specific VLAN groups. Each bit in the two-byte field represents a VLAN denomination from 1 to 16 in hexadecimal. Refer to “Setting Up a VLAN” on page 5-5 for more informa- tion.

It is strongly recommended that you do not alter these settings.

Bridge Parameters

This section describes how to set bridge parameters for the TR-in-FE.

Spanning Tree

Spanning Tree is an algorithm designed to eliminate loops in networks. The algorithm detects and logically prohibits redundant paths by placing some bridge ports in the blocking state so that only one route exits between any two LANs and therefore any two sta- tions. After Spanning Tree eliminates redundant paths, the network reconfigures and stabilizes. Any time the network topology changes, the algorithm automatically relearns the new configuration and adjusts the bridge ports accordingly. This guarantees that all stations are connected.

Priority—Priority determines the choice of port when the Switch 2000 TR has two ports connected to the same LAN, creating a loop.

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Contents For SuperStack II Switch 2000 TR For civilian agencies For units of the Department of DefenseAbout this Guide 3COM Corporation Limited Warranty Terminology About this GuideIntroduction Conventions Finding Information in this GuideOverview About the SuperStack II Switch 2000 TR TR-in-FE ModuleTR-in-FE Benefits Software Summary of TR-in-FE Module FeaturesHardware 4CHAPTER 1 Overview TR-IN-FE Concepts What is Token Ring-in-Fast Ethernet TR-in-FE?Token Ring-in-Fast Ethernet Module TR-in-FE Compared to Traditional Methods3Com Token Ring-in-Fast Ethernet System How TR-in-FE Works How TR-in-FE WorksPower IIRedundant SuperStack Token Ring Frames TunnelingRequirements 4Token Ring-in-Fast Ethernet Frame Port-Based Distribution What is a VlanVirtual LANs Vlans Advantages of Vlan8CHAPTER 2 TR-IN-FE Concepts Pre-installation Procedure Installing and Setting UP the ModuleFollowing Safety Information Installation LED Summary Post-Installation ChecksChecking the Power Supply Checking the Physical Connections Checking that the TR-in-FE Module is Installed Correctly2TR-in-FE Module Jumper Settings Jumper SettingsEntry Field Accessing Management FeaturesVT100 Console Choice FieldCorrecting Text Entries ButtonList Boxes Key Board ShortcutsConsole Menu Map Default UsersDefault Name Password Access Level 1VT100 Console Menu Map with I/O Module Detail LCD Console Switch 2000 TR bannerLogging On User Name Default Access Level PasswordAutomatic Logout Logging Off8CHAPTER 4 Accessing Management Features TR-in-FE Module Configuration Map Configuring the TR-IN-FE Module2I/O Module Screen Config Setting Up a ModuleSpanning Tree Bridge ParametersSource Routing TR Vlan Setup Screen Setting Up a VlanTR Vlan Info Setup Screen Scroll the Vlan list using the Up and Down keys TR-in-FE Module Statistics Map Monitoring the TR-IN-FE Module2TR Port Statistics Screen Statistics Overview3Sample TR Port Statistics Traffic Screen Port Statistics TrafficJam Counts Clearing Screen Counters’information de Sécurité Importante Important Safety InformationWichtige Sicherheitsinformationen Screen Access level required Screen Access Rights2APPENDIX B Screen Access Rights TR-in-FE Cable Specification TR-IN-FE Module Technical SpecificationsEnvironmental Specifications Core mm Cladding mm Numerical Aperture Does the Cable Provide Sufficient Bandwidth?Example TR-in-FE Cable Specification 4APPENDIX C TR-IN-FE Module Technical Specifications World Wide Web Site Online Technical Services3Com Bulletin Board Service Technical SupportCountry Telephone Number 3ComFacts Automated Fax ServiceSupport from Your Network Supplier 3ComForum on CompuServeCountry Telephone Number Fax Number Support from 3ComReturning Products for Repair 4APPENDIX D Technical Support Numbers Page Hardware 3Com Corporation Limited WarrantyGoverning LAW