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3Com LinkBuilder MSH User Manual

4 port ethernet bridge module
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Part No. DUA1860-0AAA01
Published November 1994
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Summary of Contents for 3Com LinkBuilder MSH

  • Page 1 UILDER THERNET RIDGE ODULE UIDE Part No. DUA1860-0AAA01 Published November 1994...
  • Page 2 3Com Corporation. 3Com Corporation reserves the right to revise this documentation and to make changes in content from time to time without obligation on the part of 3Com Corporation to provide notification of such revision or change.

  • Page 3: Table Of Contents

    How To Use This Guide Conventions Special Messages Related Publications xiii NTRODUCTION The LinkBuilder MSH The LinkBuilder MSH 4 Port Ethernet Bridge Module Managing The Bridge Bridging Why Use A Bridge? Local And Remote Bridges Bridge Network Topology 1-10 Learning, Filtering And Forwarding...
  • Page 4 The VT100 Management Interface The VT100 Bridge Screens The VT100 Bridge Menu Map Bridge Control Keys Simple Bridge Configuration 2-11 Logging On To The LinkBuilder MSH 2-12 Logging On To The Bridge 2-17 Establishing Operator Accounts 2-18 Adding Bridge Information...
  • Page 5 Custom Filter Configuration Setting Up A Host-to-Host Filter Set 3-10 Saving Host-to-Host Filters 3-12 Setting Up A Host-to-Port Filter Set 3-13 Saving Host-to-Port Filters 3-15 Setting Up A Port-to-Port Filter Set 3-16 Saving Port-to-Port Filters 3-17 Setting Up A Multicast-to-Port Filter Set 3-18 Saving Multicast-to-Port Filters 3-19...
  • Page 6 Delete Permanent Entry Transfer Permanent Entries Editing ARP Information 5-10 ARP Parameters 5-10 Add ARP Entry 5-11 Delete ARP Entry 5-12 Changing TCP Characteristics 5-13 Changing Telnet Characteristics 5-14 Port Queuing 5-16 Monitoring 5-17 Viewing General Bridge Information 5-17 Viewing Node Table Information 5-19 Node Table By Address 5-19...
  • Page 7 ETTINGS ECHNICAL NFORMATION Electrical Safety Environmental Reliability ECHNICAL UPPORT On-line Technical Services 3Com Bulletin Board Service (3ComBBS) Ask3Com on CompuServe 3ComFacts Automated Fax Service 3Com Documentation on CD-ROM Support from Your Network Supplier Support from 3Com Returning Products for Repair...
  • Page 8 NDEX ADIO REQUENCY NTERFERENCE TATEMENTS IMITED ARRANTY...

  • Page 9: About This Guide

    UIDE Introduction This guide contains all the information you need to install and use the LinkBuilder MSH 4 Port Ethernet Bridge Module. It is written for the person responsible for the management and maintenance of the network. The guide explains: How to configure the 4 Port Bridge Module.

  • Page 10: How To Use This Guide

    How To Use This Guide The following list shows where to find specific information: If you are looking for: Turn to: An introduction to the LinkBuilder MSH, the 4 Port Chapter 1 Ethernet Bridge Module, bridging and filtering How to configure a simple bridge...

  • Page 11: Conventions

    Conventions Conventions The following table lists conventions that are used throughout this guide: “Enter” vs. “Type” When the word “enter” is used in this guide, it means type something, then press the [Return] or [Enter] key. Do not press the [Return] or [Enter] key when an instruction simply says “type.”...

  • Page 12: Special Messages

    BOUT UIDE Special Messages A special format indicates notes, cautions, and warnings. These messages are defined as follows: Notes call attention to important features or instructions. CAUTION: Cautions contain directions that you must follow to avoid immediate system damage or loss of data. WARNING: Warnings contain directions that you must follow for your personal safety.

  • Page 13: Related Publications

    If you have lost or do not have a particular guide, copies can be obtained from your supplier. The following guides are particularly useful: How To Install And Use The LinkBuilder MSH/11 (DUA1800-0AAA0x) The LinkBuilder MSH Management Module Volume 1 (DUA1850-0AAA0x)
  • Page 14 BOUT UIDE DUA1860-0AAA01...

  • Page 15: Introduction

    NTRODUCTION This chapter contains the following topics: The LinkBuilder MSH The LinkBuilder MSH 4 Port Ethernet Bridge Module Managing The Bridge Bridging Bridge Filters Simple Network Management Protocol (SNMP) Installation And Removal...

  • Page 16: The Linkbuilder Msh

    The LinkBuilder MSH is an extremely versatile chassis-based hub, which enables you to connect and manage large, mixed-technology, mixed-media LANs. The basis of the LinkBuilder MSH is the chassis, into which a series of network specific modules can be installed, as shown in Figure 1-1.

  • Page 17: The Linkbuilder Msh 4 Port Ethernet Bridge Module

    The LinkBuilder MSH 4 Port Ethernet Bridge Module The LinkBuilder MSH 4 Port Ethernet Bridge Module The bridge module provides a bridge connection between the three Ethernet busses of the MSH and an external port (the bridge module's transceiver module), as shown in Figure 1-2.
  • Page 18 1: I HAPTER NTRODUCTION The bridge module provides: Connection to each Ethernet bus in the MSH. An external connection by transceiver module. LEDs for indicating bridge activity and diagnosing possible problems. Standard IEEE 802.1 Part D transparent bridging. Additional custom bridge filtering: Host-to-Host filtering Host-to-Port filtering Port-to-Port filtering...
  • Page 19 Each port has a row of three LEDs; transmit (TX), receive (RX) and enabled (EN). Ports with numbers signify the Ethernet bus in the LinkBuilder MSH chassis to which the port is connected. The unnumbered row is for the external port, the Transceiver Module.
  • Page 20 A Transceiver Module can be fitted to the bridge, providing its fourth port, as shown in Figure 1-4. A range of Modular Transceivers are produced by 3Com, allowing you flexibility when deciding on network connections and cabling: 3C12060 Female AUI Transceiver Module 3C12065 Fiber Transceiver Module (ST)

  • Page 21: Managing The Bridge

    To use the VT100 management interface: Connect a VT100 terminal or VT100 terminal emulator directly to the serial port on the display panel of the LinkBuilder MSH. Use a VT100 terminal emulator over a network, via Telnet. To manage the bridge, you must have a LinkBuilder MSH Management Module (3C18500) with software version 2.1 or...

  • Page 22: Bridging

    1: I HAPTER NTRODUCTION Bridging This section describes bridges and how they work. Why Use A Bridge? Bridges provide a way of joining two or more networks together to form a single logical and physical network. You can overcome various network restrictions that apply to large individual networks by bridging smaller networks together.

  • Page 23: Local And Remote Bridges

    Local And Remote Bridges There are two main types of bridge, local and remote. The LinkBuilder MSH 4 Port Ethernet Bridge Module is a local bridge. Local bridges are used for bridging networks on the same site, as shown in Figure 1-6.

  • Page 24: Bridge Network Topology

    1-10 1: I HAPTER NTRODUCTION Bridge Network Topology The topology of a network is essentially its layout; how its component parts are inter-connected. The topology of your network is dependent on the amount of bridges that you use and the way in which you use them. If you use one 4 Port Ethernet Bridge Module, you may have a star topology.
  • Page 25 Bridging 1-11 Figure 1-9 An Example Topology DUA1860-0AAA01...

  • Page 26: Learning, Filtering And Forwarding

    1-12 1: I HAPTER NTRODUCTION Learning, Filtering And Forwarding Transparent bridges remain transparent to the network segments, treating them as one overall network. The main operations of a transparent bridge are learning, filtering and forwarding. These operations are 802.1 bridge features and enable it to control the flow of traffic to each network segment.
  • Page 27 Bridging 1-13 Figure 1-11, Figure 1-12, Figure 1-13 Figure 1-14 illustrate how a bridge learns device addresses and uses address lists to reduce unnecessary network traffic. Figure 1-11: The bridge does not know what devices are on the network. Figure 1-11 An Example Network Figure 1-12: Device A, connected to port 1, transmits a packet for device B.
  • Page 28 1-14 1: I HAPTER NTRODUCTION Figure 1-13: Device C, connected to port 2, transmits a packet for device A. The bridge learns the address of device C and recognizes the address of device A, so it forwards the packet to port 1.
  • Page 29 Bridging 1-15 The bridge performs ageing on address list entries. If a port has not received a packet from a device within a configured time (the ageing time), the device's address will be removed from the port's address list. This helps the bridge to efficiently remember devices that communicate frequently without having to cope with devices that communicate infrequently or are no longer there.

  • Page 30: Spanning Tree Algorithm And Protocol (Stap)

    1-16 1: I HAPTER NTRODUCTION Spanning Tree Algorithm And Protocol (STAP) You can make your network more resilient by adding bridges and network segments. If a network segment or bridge fails, traffic can still travel through the network by using the additional bridges and network segments.
  • Page 31 Bridging 1-17 In a bridged network, a root bridge is elected to control the other bridges. The root bridge is made aware of any active loops by consulting the other bridges. The STAP constructs a spanning tree which provides unique paths between all devices in the network, and applies it by putting various bridges' ports in to a blocking state, as shown in Figure...
  • Page 32 1-18 1: I HAPTER NTRODUCTION The STAP is also capable of constructing a new spanning tree should the unique path fail, see Figure 1-17, leading to quick network recovery. Figure 1-17 Path Fails, Bridge Port Re-enabled DUA1860-0AAA01...
  • Page 33 Bridging 1-19 Network resilience obviously leads to some path redundancy, as shown in Figure 1-18. Figure 1-18 Network Resilience For more detailed STAP information, please refer to the latest revision of the IEEE 802.1 Part D standard. DUA1860-0AAA01...

  • Page 34: Bridge Filters

    1-20 1: I HAPTER NTRODUCTION Bridge Filters The LinkBuilder MSH 4 Port Ethernet Bridge Module allows the use of customised filtering, which can be used in addition to basic transparent filtering, as explained in Learning, Filtering And Forwarding on page 1-12.
  • Page 35 Bridge Filters 1-21 Figure 1-19: A filter set for port 2 has been set up allowing device A to communicate through the bridge and out of that port. No other device can communicate through the bridge and out of that port.
  • Page 36 1-22 1: I HAPTER NTRODUCTION Figure 1-21: Device B transmits a packet for device C. The bridge knows that device C is connected to port 2, so it checks that port's filter set. Communication is not allowed, so it filters the packet.

  • Page 37: Filter Sets

    Bridge Filters 1-23 Filter Sets A filter set is a group of devices that are allowed to communicate with each other. The 4 Port Ethernet Bridge Module's default filter sets let all hosts and ports communicate. If you want to restrict communication, you must edit the default filter sets.

  • Page 38: Host-To-Port Filtering

    1-24 1: I HAPTER NTRODUCTION Figure 1-22 illustrates a host-to-host filter example, and shows four network segments connected by a bridge. A filter set has been set up allowing communication between devices A and D only, through the bridge. Every packet received by the bridge has its source address and destination address checked.
  • Page 39 Bridge Filters 1-25 Exclusion means that devices in the set cannot communicate out of that port, and all other devices can. If the set is empty, all devices can communicate out of that port. The default host group is contained in all host-to-port filter sets following an initialization.

  • Page 40: Port-To-Port Filtering

    1-26 1: I HAPTER NTRODUCTION Port-to-Port Filtering A port-to-port filter set is a group of ports that are allowed to communicate through the bridge. There is a port-to-port filter set for each bridge port. Figure 1-24 Figure 1-25 illustrate a port-to-port filter example.

  • Page 41: Multicast-To-Port Filtering

    Bridge Filters 1-27 Changes made to port-to-port filter sets are mirrored by the other port-to-port filter sets. For example, if ports 1 and E are added to port 3's filter set, port 3 is automatically added to port 1's and port E's filter sets.

  • Page 42: Bit Filtering

    1-28 1: I HAPTER NTRODUCTION Bit Filtering Bit filters selectively filter out traffic based on bit values occurring in the first 64 bytes of each frame. This provides extremely flexible filtering. You can test any combination of bits within a six-byte long field falling within the first 64 bytes of the frame and beginning on a byte boundary.

  • Page 43: Enabling Custom Filtering

    Bridge Filters 1-29 Enabling Custom Filtering You have to enable custom filtering before it becomes effective. You can enable and disable all custom filters or individual custom filters with ease. As custom filtering can involve multiple checking of packets, it can have an adverse impact on bridge performance in a high traffic rate environment.

  • Page 44: Simple Network Management Protocol (Snmp)

    1-30 1: I HAPTER NTRODUCTION Simple Network Management Protocol (SNMP) SNMP is an application-level protocol for managing products such as bridges on TCP/IP networks. You can issue requests using an SNMP application. The application passes the requests to the SNMP agent software on the device to be managed. The agent carries out the requests and sends responses to the application.

  • Page 45: Installation And Removal

    Anti-Static Information To avoid damaging the module: Do not remove the module from its anti-static packaging until you are ready to install it into the LinkBuilder MSH chassis. Do not touch the pins, leads, connections or any components on the module.
  • Page 46 1-32 1: I HAPTER NTRODUCTION DUA1860-0AAA01...

  • Page 47: Getting Started

    ETTING TARTED This chapter contains the following topics: The VT100 Management Interface The VT100 Bridge Menu Map Bridge Control Keys Simple Bridge Configuration IP Address Configuration SNMP Configuration...

  • Page 48: Introduction

    2: G HAPTER ETTING TARTED Introduction This chapter describes setting up the bridge for the first time. If you have not set up the bridge before, or are setting it up again after initializing NVRAM, you should read this chapter. The chapter contains the following information: A general introduction to the VT100 Management Interface, which is used to manage the bridge.

  • Page 49: The Vt100 Management Interface

    The screens are grouped hierarchically. For a complete menu map The VT100 Bridge Menu Map on page of the bridge screens, see 2-6. The menu map also appears on The LinkBuilder MSH 4 Port Ethernet Bridge Module 3C18600 Quick Reference Guide, that accompanies this manual.

  • Page 50: The Vt100 Bridge Screens

    2: G HAPTER ETTING TARTED The VT100 Bridge Screens The VT100 bridge screens have the same general layout. The components of a bridge screen are shown in Figure 2-1. Figure 2-1 Bridge Screen Components The components are: A - Screen title. The boxed words starting in the top left hand corner of the screen.
  • Page 51 The VT100 Management Interface E - Remote login identifier. The name of the user currently remotely logged on to the bridge. F - Input area. The line below the screen area provides the data entry location for input screens. The area starts with a short description of the highlighted field.

  • Page 52: The Vt100 Bridge Menu Map

    2: G HAPTER ETTING TARTED The VT100 Bridge Menu Map The VT100 bridge menu map, as shown in Figure 2-2, shows the links between the bridge management screens. The italic number at the bottom left of each screen box is the page in this manual, where you will find the description of that screen.
  • Page 53 The VT100 Bridge Menu Map Operators with Administrator privileges are unrestricted. Operators with Operator privileges cannot configure the bridge, initialize NVRAM, or reset the bridge (the Administrative Screens). DUA1860-0AAA01...

  • Page 54: Bridge Control Keys

    2: G HAPTER ETTING TARTED Bridge Control Keys There are special control keys for operating the bridge. These are different to the MSH management module control keys and should be used from the time you log on to the bridge. For [Ctrl] key sequences, hold down the [Ctrl] key while pressing the specified key.
  • Page 55 Bridge Control Keys Table 2-1 Bridge Control Keys Description Return to Main Menu [Ctrl] + [T] Returns you to the Main Menu. [Ctrl] + [C] [Ctrl] + [Y] [Esc] [T] Return to MSH Management Module [Ctrl] + [P] When logged on locally, this returns you to the MSH Management Module screens.
  • Page 56 2-10 2: G HAPTER ETTING TARTED Table 2-1 Bridge Control Keys Description Refresh screen [Ctrl] + [V] Refreshes the screen. [Esc] [V] Next step [Esc] [N] Takes you to the next menu or screen, or returns you from help. Using this from a menu, takes you to the screen associated with the highlighted item.

  • Page 57: Simple Bridge Configuration

    Initially, the bridge has no IP address. Without a unique IP address, it cannot be remotely managed, so you must first log on to the LinkBuilder MSH, then log on to the bridge, then set up a unique IP address.

  • Page 58: Logging On To The Linkbuilder Msh

    2: G HAPTER ETTING TARTED Logging On To The LinkBuilder MSH Logging on to the LinkBuilder MSH is also described in The LinkBuilder MSH Management Module manual. Connect to the LinkBuilder MSH. The Main Banner appears, as shown in Figure 2-3.
  • Page 59 2-13 The Logon screen appears and stays displayed until a valid User Name and Password have been entered, as shown in Figure 2-4. Enter a User Name and Password for the LinkBuilder MSH. Figure 2-4 LinkBuilder MSH Logon Screen DUA1860-0AAA01...
  • Page 60 2-14 2: G HAPTER ETTING TARTED When you are logged on to the LinkBuilder MSH, the Main Menu appears, as shown in Figure 2-5. It offers various LinkBuilder MSH management options. The LOGOFF option closes down the session, allowing the interface to ‘sleep’.
  • Page 61 Simple Bridge Configuration 2-15 The Service Selection screen appears, listing all the services within the LinkBuilder MSH Chassis with the number of the slot or backplane to which it is attached, as shown in Figure 2-6. Highlight 4 PORT .3 BRIDGE, press [Space] and select OK to select the LinkBuilder MSH 4 Port Ethernet Bridge Module.
  • Page 62 The Address Table screen appears, showing default address information for the bridge, as shown in Figure 2-7. If the bridge's IP address is unconfigured, a random IP address is shown. Select MANAGE to continue. Figure 2-7 LinkBuilder MSH Address Table DUA1860-0AAA01...

  • Page 63: Logging On To The Bridge

    Simple Bridge Configuration 2-17 Logging On To The Bridge When you connect to the bridge, the Operator Login screen appears, as shown in Figure 2-8. Until it is configured, the bridge has no Operator IDs or Passwords, meaning that the bridge has no security.

  • Page 64: Establishing Operator Accounts

    2-18 2: G HAPTER ETTING TARTED Establishing Operator Accounts When you have logged on to the bridge, the bridge's Main Menu appears, offering various management options, as shown in Figure 2-9. The bridge's security is disabled if no administrative operator accounts have been set up, so you should set up these accounts first.
  • Page 65 Simple Bridge Configuration 2-19 The Configuration menu appears, as shown in Figure 2-10. You can access all the configuration screens and sub-menus from this menu. Select SYSTEM. Figure 2-10 Configuration Menu The System menu appears. Select OPERATOR ACCOUNTS from the System menu. DUA1860-0AAA01...
  • Page 66 2-20 2: G HAPTER ETTING TARTED The Operator Accounts screen appears, listing the operator accounts that are set up for the bridge, see Figure 2-11. You can set up 60 operator accounts for the bridge. Enter the number of the operator account you want to set up. Figure 2-11 Operator Accounts No: Display Field.
  • Page 67 Simple Bridge Configuration 2-21 Account Number: Text Field. Enter the account number of the operator you want to set up. You can set up from 1 to 60 accounts. After entering an account number, the Edit User Accounts screen appears. DUA1860-0AAA01...
  • Page 68 2-22 2: G HAPTER ETTING TARTED The Edit User Accounts screen appears with information on the operator account you entered in the Operator Accounts screen, as shown in Figure 2-12. You use this screen for entering and modifying operator account information. Any existing information is displayed.
  • Page 69 Simple Bridge Configuration 2-23 Operator Privilege: Choice Field ( A / O ). Designate the privileges for the operator. A is for administrator and O is for operator. Bridge operators can be set up with either Administrator or Operator privileges. Operators with Administrator privileges are unrestricted.

  • Page 70: Adding Bridge Information

    2-24 2: G HAPTER ETTING TARTED Adding Bridge Information You should provide general device information for your bridge the first time you set it up. This information is required by all MIB II conformant devices and is generally useful because it includes the location of the bridge and the name of the person responsible for it (useful if the bridge is not operating correctly).
  • Page 71 Simple Bridge Configuration 2-25 System Contact: Text Field. Enter the name of the person who is responsible for the bridge. This is a string of 1 to 16 characters. Changes to this field are only saved during a bridge reset, and take effect from then on.

  • Page 72: Saving And Making Changes Effective

    2-26 2: G HAPTER ETTING TARTED Saving And Making Changes Effective Some of the changes you can make to the bridge are not saved if you simply log off. However, not all fields require a bridge reset to save them and make them effective. The field descriptions that accompany each screen, in this manual, describe the necessary procedures.

  • Page 73: Erasing All Changes

    Simple Bridge Configuration 2-27 Erasing All Changes If you want to erase all the changes made to the bridge since logging on, simply log off the bridge. However, if you want to erase all the changes ever made to the bridge, you must initialize NVRAM (Non Volatile Random Access Memory) and reset the bridge.

  • Page 74: Logging Off The Bridge

    2-28 2: G HAPTER ETTING TARTED Logging Off The Bridge Selecting LOGOUT from the Main Menu will log you off the bridge and return you to the display you had before logging on. Any changes that have been made since logging on will be erased.

  • Page 75: Ip Address Configuration

    This section describes how to assign an IP address to the bridge. When the bridge has an IP address, you can remotely manage it via Telnet, and will not need to go through the LinkBuilder MSH. Telnet is a TCP/IP application. SNMP also requires the bridge to have an IP address.

  • Page 76: Bridge Connections

    If you are logging on from a remote host, the terminal must support VT100. Logging On To The Bridge You can log on to the bridge locally (via the LinkBuilder MSH) and remotely (via Telnet). The bridge can accept: Either a local or a remote log on.

  • Page 77: Setting Up Remote Access

    IP Address Configuration 2-31 Setting Up Remote Access Initially, the bridge has no IP addressing information. When set up, the IP address identifies the bridge. The IP Addresses screen is used for setting up an IP address for the bridge so that other devices can communicate with its management agent.

  • Page 78: Active

    2-32 2: G HAPTER ETTING TARTED Active IP Address: Display Field. The bridge's current IP address. A line of dashes indicates that no IP address has been assigned to the bridge. Subnet Mask: Display Field. The bridge's current subnet mask. Next Reset IP Address: Text Field.

  • Page 79: Static Routes

    IP Address Configuration 2-33 Static Routes If you are using a routed network, you will need to enter a default gateway to ensure remote communication with the bridge. A more resilient network can be set up by defining a set of static routes.
  • Page 80 2-34 2: G HAPTER ETTING TARTED Item: Text Field. The number of a configured static route or 0 (to enter a new route). Static routes are sorted by IP address and assigned numbers according to their positions in the sorted list. Entering the number of a configured static route causes that route to be displayed.
  • Page 81 IP Address Configuration 2-35 Preference: Text Field. A whole number from 0 to 255, designating the rank to be assigned to the route specified by the DESTINATION HOST and GATEWAY fields. 0 represents the most desirable route, 255 represents the least desirable route. The default is 50 .

  • Page 82: Assigning Host Name / Ip Address Pairs

    2-36 2: G HAPTER ETTING TARTED Assigning Host Name / IP Address Pairs You can assign symbolic names (host names) for devices that can communicate with or from the bridge. If a device has an IP address, a host name can be assigned to it. This host name can then be used instead of the IP address to identify the device, when using the bridge.
  • Page 83 IP Address Configuration 2-37 IP Address: Text Field. Enter the IP address for the device. It must be in decimal and of the form nnn.nnn.nnn.nnn. Changes to this field are only saved during a bridge reset, and take effect from then on.

  • Page 84: Using Ping To Test Connections

    If you have just set up address information for the bridge, reset the bridge to save the information and for it to take effect. We recommend that you PING the LinkBuilder MSH Management Module, in the same chassis as the bridge, to test that PING is working correctly.
  • Page 85 IP Address Configuration 2-39 Select PING from the Applications menu. The Ping Settings screen appears, as shown in Figure 2-19. Enter the IP address or host name of the remote device and confirm the packet size and timeout parameters (modify these only if necessary).
  • Page 86 2-40 2: G HAPTER ETTING TARTED The Ping screen appears, as shown in Figure 2-20, after the information for the Ping Settings screen has been supplied. The Ping screen immediately starts displaying status messages when information is received. When you've finished with the Ping screen, press [Enter] or [Return] to exit from it.
  • Page 87 IP Address Configuration 2-41 Packets Received: Display Field. The number of ICMP echo response messages that have been received from the destination address. Minimum: Display Field. The shortest amount of time (in milliseconds) that elapsed between sending an ICMP echo request and receiving an ICMP echo response.

  • Page 88: Telnet Log On To Another Ip Device From The Bridge

    The bridge has Telnet capabilities, allowing you to remotely log on to an IP device. This is especially useful for logging on to other LinkBuilder MSH 4 Port Bridge Modules. However, the bridge does not always allow you to Telnet out. For information on when...
  • Page 89 IP Address Configuration 2-43 If the Remote Connect screen appears, as shown in Figure 2-21, you are allowed to Telnet out from the bridge. Enter the host name or IP address of the device you want to log on to. If you use a host name, it must appear in the bridge's host table.

  • Page 90: Talking To Another Bridge User

    2-44 2: G HAPTER ETTING TARTED Talking To Another Bridge User The bridge can accept two users, one local and one remote. If both users are present, they can exchange messages via the Chat screen. The Chat screen, as shown in Figure 2-22, is intended for exchanging uncomplicated information:...

  • Page 91: Telnet Suspension

    IP Address Configuration 2-45 Telnet Suspension You can suspend your Telnet session from the bridge at any time. You may want to do this if you want to return to the bridge but stay connected to the remote device. To suspend a remote session, press [Ctrl] + [ ] ]. You will be returned to the Main Menu of the bridge.

  • Page 92: Snmp Configuration

    2-46 2: G HAPTER ETTING TARTED SNMP Configuration This section describes configuration of the SNMP agent on the bridge. When the SNMP agent has been configured, SNMP applications can obtain information from it about the bridge. This section describes how to: Configure the basic characteristics of each community and globally enable or disable the Authentication Failure trap.

  • Page 93: Traps

    SNMP Configuration 2-47 Traps An SNMP agent can send messages, traps, when exceptional events occur. Traps include the name of the community involved in the event. They are sent to an IP address that you define for each community during configuration of the agent. The main advantage of traps is that you do not have to constantly monitor the bridge because it alerts you when any exceptional events occur.

  • Page 94: Configuring Basic Community Characteristics

    2-48 2: G HAPTER ETTING TARTED Configuring Basic Community Characteristics Select CONFIGURATION from the Main Menu and then NETWORK PROTOCOL from the Configuration menu. Select SNMP from the Network Protocol menu to get the Configure SNMP menu. Select COMMUNITIES from the Configure SNMP menu. The SNMP Community Basic Configuration screen appears, as shown in Figure...
  • Page 95 SNMP Configuration 2-49 Authentication Failure Trap: Text Field ( e / d ). Enable or disable the authentication failure trap for the SNMP agent. Enter e to enable, or enter d to disable. The default is disable. If the trap is enabled, the agent generates a trap message whenever a client tries to access it using a community name you have not defined.
  • Page 96 2-50 2: G HAPTER ETTING TARTED Access: Text Field ( r/o / r/w ). Enter the access mode for the community's MIB view. The effect this has on operations permissible for the community depends on the ACCESS: in the MIB definition of the object. Enter r/o to specify that the community can perform read operations (GET and TRAP) on the value of a MIB object in the MIB view, if the object's MIB ACCESS: is read-write or...

  • Page 97: Configuring Community Traps

    SNMP Configuration 2-51 Configuring Community Traps Select COMMUNITY TRAPS from the Configure SNMP menu. The SNMP Community Trap Configuration screen appears, as shown in Figure 2-25, displaying the existing community name (configured in the SNMP Community Basic Configuration screen). You use this screen for configuring the community name, enabling or disabling traps, defining the device to which the agent is to send trap messages, and defining the UDP port to which the agent is to send trap messages.
  • Page 98 2-52 2: G HAPTER ETTING TARTED IP Address / Host Name: Text Field. The host to which traps pertaining to the community name are to be sent. Specify either an IP address in the dotted decimal notation (nnn.nnn.nnn.nnn), or the name of the host that has been defined in the host table (via the IP Host Table screen).
  • Page 99 SNMP Configuration 2-53 Enable: Text Field ( y / n ). Enter y to enable, or n to disable the Authentication Failure, Cold Start, Interface Up, Interface Down, New Root and Topology Change traps. An Authentication Failure trap is generated when an SNMP client has tried to access the agent using a community name the agent does not recognize.
  • Page 100 2-54 2: G HAPTER ETTING TARTED DUA1860-0AAA01...

  • Page 101: Advanced Bridging

    DVANCED RIDGING This chapter contains the following topics: Spanning Tree Configuration Custom Filter Configuration...

  • Page 102: Introduction

    3: A HAPTER DVANCED RIDGING Introduction This chapter describes how to set up the bridge's advanced features. If you have not previously set up the bridge, read Chapter 2. Spanning Tree Configuration The Spanning Tree Algorithm and Protocol (STAP) is explained in the IEEE Computer Society's MAC Bridges P802.1D document.

  • Page 103: Spanning Tree Bridge Configuration

    Spanning Tree Configuration Spanning Tree Bridge Configuration Select CONFIGURATION from the Main Menu. Select BRIDGES from the Configuration menu. Select SPANNING TREE from the Bridges menu. The Spanning Tree screen appears, as shown in Figure 3-1. You use this screen for editing the bridge's spanning tree information. The screen is split and shows the spanning tree information for this bridge (on the left) and the current root bridge (on the right).
  • Page 104 3: A HAPTER DVANCED RIDGING ID: Display Field. The identification number for the bridge. The ID number uniquely identifies each bridge. The number is a combination of the lowest Ethernet device address on the bridge and a hexadecimal representation of the PRIORITY field. The Ethernet device address is hard-coded in the Ethernet chip and cannot be changed.
  • Page 105 Spanning Tree Configuration Hello Time: Text Field. Enter the hello time for the bridge. The hello time is the amount of time the bridge pauses between sending spanning tree configuration C-BPDUs. The hello time must be between 1 and 10 seconds and must be lower than the maximum age.

  • Page 106: Spanning Tree Port Configuration

    3: A HAPTER DVANCED RIDGING Spanning Tree Port Configuration Select SPANNING PORT from the Bridges menu. The Port Settings screen appears, as shown in Figure 3-2. You use this screen for editing various port spanning tree information. The screen is split and shows the spanning tree information for this bridge (on the left) and the current root bridge (on the right).
  • Page 107 Spanning Tree Configuration Port: Text Field. Enter the name of the port who's spanning tree parameters you want to change. Use 1 , 2 , 3 or E . ID: Display Field. The identification number for the port. The port's ID is the same as the bridge's ID, which is a combination of two numbers, the bridge priority and the Ethernet address of the bridge.
  • Page 108 3: A HAPTER DVANCED RIDGING Path Cost: Text Field. Enter the path cost. The path cost represents the performance cost of sending information through a port and measures the impact of sending packets through the network. The path cost setting establishes a hierarchy among the ports of the spanning tree topology.

  • Page 109: Custom Filter Configuration

    Custom Filter Configuration Custom Filter Configuration You can control the traffic that flows through the bridge by using the bridge's custom filters. For example, you can prevent communication between specific devices, and allow only TCP/IP communication between specific bridge ports. The basic concepts of custom filtering are explained in Bridge Filters on page 1-20.

  • Page 110: Setting Up A Host-To-Host Filter Set

    3-10 3: A HAPTER DVANCED RIDGING Setting Up A Host-to-Host Filter Set Select CONFIGURATION from the Main Menu. Select BRIDGES from the Configuration menu. Select BRIDGE FILTERS from the Bridges menu. The Bridge Filters menu lists each filter option. Selecting the relevant filter will take you through to that filter's setup screen.
  • Page 111 Custom Filter Configuration 3-11 Set Number: Text Field. Enter the number of the filter set you want to set up. You can use any number from 1 to 32 but remember that set number 1 is the absolute exclusion set. Press [Return] to accept the set number.

  • Page 112: Saving Host-To-Host Filters

    3-12 3: A HAPTER DVANCED RIDGING Saving Host-to-Host Filters When you have set up your filter sets, you must use the Filter Options screen to save them. Exit from the Host-to-Host screen and select FILTER SWITCHES from the Bridge Filters menu. You also use the Filter Options screen for enabling and disabling filters.

  • Page 113: Setting Up A Host-To-Port Filter Set

    Custom Filter Configuration 3-13 Setting Up A Host-to-Port Filter Set Select HOST-TO-PORT from the Bridge Filters menu. The Host-to-Port screen appears, as shown in Figure 3-4. You use this screen for setting up a port's host-to-port filter set. The screen displays the hosts included in the filter set of the port denoted in the PORT NAME field.
  • Page 114 3-14 3: A HAPTER DVANCED RIDGING Set Type: Text Field ( inclusion / exclusion ). Enter the filter set's type. You can define a filter set by inclusion or exclusion. Enter inclusion to define the filter set as inclusion, or exclusion to define the filter set as exclusion.

  • Page 115: Saving Host-To-Port Filters

    Custom Filter Configuration 3-15 Saving Host-to-Port Filters When you have set up your filter sets, you must use the Filter Options screen to save them. Exit from the Host-to-Port screen and select FILTER SWITCHES from the Bridge Filters menu. You also use the Filter Options screen for enabling and disabling filters.

  • Page 116: Setting Up A Port-To-Port Filter Set

    3-16 3: A HAPTER DVANCED RIDGING Setting Up A Port-to-Port Filter Set Select PORT-TO-PORT from the Bridge Filters menu. The Port-to-Port screen appears, as shown in Figure 3-5. You use this screen for setting up a port's port-to-port filter set. The screen displays the ports included in the filter set of the port denoted in the SET PORT SYMBOLIC NAME field.

  • Page 117: Saving Port-To-Port Filters

    Custom Filter Configuration 3-17 Set Name: Text Field. This is optional. Enter a name for the filter set. The set name helps you identify the set. If you enter a name that is already used for a port-to-port filter set, that filter set will be displayed.

  • Page 118: Setting Up A Multicast-To-Port Filter Set

    3-18 3: A HAPTER DVANCED RIDGING Setting Up A Multicast-to-Port Filter Set Select MULTICAST from the Bridge Filters menu. The Multicast screen appears, as shown in Figure 3-6. You use this screen for setting up a port's multicast-to-port filter set. The screen displays the ports included in the filter set of the port denoted in the SET PORT SYMBOLIC NAME field.

  • Page 119: Saving Multicast-To-Port Filters

    Custom Filter Configuration 3-19 Set Name: Text Field. This is optional. Enter a name for the filter set. The set name helps you identify the set. If you enter a name that is already used for a multicast-to-port filter set, that filter set will be displayed.

  • Page 120: Setting Up A Protocol Filter Set

    3-20 3: A HAPTER DVANCED RIDGING Setting Up A Protocol Filter Set Select PROTOCOL from the Bridge Filters menu. The Protocol screen appears, as shown in Figure 3-7. You use this screen for setting up a protocol filter set. The screen displays protocol families (on the left) and individual protocols (on the right), included in the filter set of the port denoted in the SET PORT SYMBOLIC NAME field.
  • Page 121 Custom Filter Configuration 3-21 permit/deny: Text Field ( permit / deny ). Denote whether you want the protocols listed as members of the filter set to be forwarded (permitted) or filtered (denied). Enter permit to forward all packets with protocols listed as members, or deny to filter all packets with protocols listed as members.

  • Page 122: Saving Protocol Filters

    3-22 3: A HAPTER DVANCED RIDGING Saving Protocol Filters When you have set up your filter sets, you must use the Filter Options screen to save them. Exit from the Protocol screen and select FILTER SWITCHES from the Bridge Filters menu. You also use the Filter Options screen for enabling and disabling filters.

  • Page 123: Setting Up A Bit Filter

    Custom Filter Configuration 3-23 Setting Up A Bit Filter Select BIT FILTERS from the Bridge Filters menu. The Configure Bit Filters screen appears, as shown in Figure 3-8. You use this screen for setting up bit filters, of which you can have up to five input and five output bit filters.
  • Page 124 3-24 3: A HAPTER DVANCED RIDGING Function: Text Field ( O / I / A / Dn / En / n / S / H ). Enter O to choose the output filter type, or I to choose the input filter type. Press [Return].
  • Page 125 Custom Filter Configuration 3-25 Byte Offset: Text Field. Defines the location of the beginning of VALUE as the number of bytes from the beginning of the frame. It can be a number from 0 to 58. For example, a byte offset of 12 lines up VALUE with the Ethernet type field, as shown in Figure 3-9.

  • Page 126: Saving Bit Filters

    3-26 3: A HAPTER DVANCED RIDGING Saving Bit Filters When you have set up your bit filters, you can use the Configure Bit Filters screen or the Filter Options screen to save them. To save bit filters with the Configure Bit Filters screen, enter S for the FUNCTION: field.

  • Page 127: The Host Filtering Table

    Custom Filter Configuration 3-27 The Host Filtering Table It can be confusing to know which host-to-host and host-to-port filter sets devices are in. All devices entered into these filter sets are added to the bridge's host filtering table. The Host Filter Info screen is a very useful screen which uses this host filtering table to show which sets devices are in.
  • Page 128 3-28 3: A HAPTER DVANCED RIDGING Table Size: Display Field. The number of devices in the host filtering table (including the default host). Add htoh: Text Field. Enter the number of the host-to-host set you want to add the device to. Enter 0 if you do not want to add the device to any host-to-host set.

  • Page 129: Saving Host Filtering Table And Filter Set Changes

    Custom Filter Configuration 3-29 Saving Host Filtering Table And Filter Set Changes Use the Filter Options screen to save any changes made. Exit from the Host Filter Info screen and select FILTER SWITCHES from the Bridge Filters menu. You also use the Filter Options screen for enabling and disabling filters.

  • Page 130: Saving And Turning Filters On And Off

    3-30 3: A HAPTER DVANCED RIDGING Saving And Turning Filters On And Off You will need to turn bridge filters on for them to take effect. You can turn them all on individually or all at once. Select FILTER SWITCHES from the Bridge Filters menu. The Filter Options screen appears, as shown in Figure 3-11.
  • Page 131 Custom Filter Configuration 3-31 To disable all filters: 1 Enter off for the FILTERING ON/OFF field. 2 Reset the bridge. In all cases, resetting the bridge causes the desired filtering to take effect. Any changes to filter sets that are in operation, take effect immediately.
  • Page 132 3-32 3: A HAPTER DVANCED RIDGING DUA1860-0AAA01...

  • Page 133: Monitoring

    ONITORING This chapter contains the following topics: Checking Bridge Statistics Checking Port Activity Viewing Ethernet Statistics Checking User Access...

  • Page 134: Introduction

    4: M HAPTER ONITORING Introduction This chapter describes simple checks you can make at regular intervals to ensure the bridge and network are working as you intend. If you want information on other monitoring screens, refer to Chapter 5. Monitoring the bridge and network is a good way of ensuring that the bridge and network are working as you intend.

  • Page 135: Checking Bridge Statistics

    Checking Bridge Statistics Checking Bridge Statistics Select MONITORING from the Main Menu. Select BRIDGES from the Monitoring menu. Select BRIDGE STATISTICS from the Bridges menu. The Bridge Statistics screen appears, as shown in Figure 4-1. You use this screen for monitoring the various port and spanning tree parameters.
  • Page 136 4: M HAPTER ONITORING Port State: Display Field. Displays the ports and their present state. The possible states are MOS , Forwarding , Blocking , Listening and Learning . The external port may go into a disconnected state ( DCONN ) when a segment has not been attached, or a transceiver module is not fitted.

  • Page 137: Rcvd

    Checking Bridge Statistics Learning means that the port is one step closer to bridging packets. Since the active topology may still be changing, a port in this state receives packets but does not bridge them. However, because the active topology is more stable than when the port is in the listening state, the port participates in the learning process of its bridge.

  • Page 138: Pkts

    4: M HAPTER ONITORING Pkts Filter: Display Field. The number of packets filtered by the bridge. Fwd: Display Field. The number of packets forwarded by the bridge. Also counts flooded packets. Flood: Display Field. The number of packets flooded by the bridge, regardless of whether they are filtered by ports.
  • Page 139 Checking Bridge Statistics There are three major observations you can make from the Bridge Statistics screen: Note the status of each port. You can check the status of each port to see if it is abnormal. Note the overall traffic. Occasional errors and overruns are normal in busy networks but you should investigate unusually high numbers in these fields.

  • Page 140: Checking Port Activity

    4: M HAPTER ONITORING Checking Port Activity You can monitor individual bridge port activity for more specific traffic information if you suspect a problem with a port. Select BRIDGE PORT STATS from the Bridges menu. The Bridge Port Statistics screen appears, as shown in Figure 4-2.
  • Page 141 Checking Port Activity Averaging: Display Field. This field displays whether the averaging feature has been turned on or off . If it is on , the number of packets or bytes displayed on this screen reflect averages per second. If it is off , the screen displays the numbers of packets or bytes accumulated since power-up.

  • Page 142: Rcvd

    4-10 4: M HAPTER ONITORING Listening means that the port is preparing to enter the active topology. At this point the port is not used for bridging packets, but C-BPDUs are received and transmitted on it, and it is included in the spanning tree calculations.

  • Page 143: Pkts

    Checking Port Activity 4-11 Pkts Filter: Display Field. The number of packets filtered by the port. Fwd: Display Field. The number of packets forwarded by the port. Also counts flooded packets. Flood: Display Field. The number of packets flooded by the port, regardless of whether they are filtered by ports.

  • Page 144: Viewing Ethernet Statistics

    4-12 4: M HAPTER ONITORING Viewing Ethernet Statistics You can use the Ethernet Statistics screen to check for suspected hardware problems on a port. Select MONITORING from the Main Menu. Select PHYSICAL INTERFACES from the Monitoring menu. Select ETHER STATISTICS from the Physical Interfaces menu.

  • Page 145: Received

    Viewing Ethernet Statistics 4-13 Received Bytes: Display Field. The number of bytes received by the port. Packets: Display Field. The number of packets received by the port. Multicasts: Display Field. The number of multicast packets received by the port. Broadcasts: Display Field. The number of broadcast packets received by the port.

  • Page 146: Transmitted

    4-14 4: M HAPTER ONITORING Overflow: Display Field. Due to exceptional loading conditions, the bridge has become overloaded and packets have been lost. Buffer: Display Field. Due to exceptional loading conditions, the bridge has become overloaded and packets have been lost. Transmitted Bytes: Display Field.
  • Page 147 Viewing Ethernet Statistics 4-15 Deferrals: Display Field. The total number of deferrals on this port. Carrier Loss: Display Field. During a transmission, carrier loss was detected. Underflow: Display Field. Due to exceptional loading conditions, the bridge has become overloaded and packets have been lost. Buffer: Display Field.

  • Page 148: Checking User Access

    4-16 4: M HAPTER ONITORING Checking User Access Select MONITORING from the Main Menu. Select SYSTEM from the Monitoring menu. Select LOGIN HISTORY from the System menu. The Login History screen appears, as shown in Figure 4-4. You use this screen to view details of logins since the bridge was last reset. This is useful for detecting attempted security breaches.
  • Page 149 Checking User Access 4-17 Number of unsuccessful logins: Display Field. The number of logins since the last bridge reset. An unsuccessful login can result from an incorrect entry of an operator ID or password. DUA1860-0AAA01...
  • Page 150 4-18 4: M HAPTER ONITORING DUA1860-0AAA01...

  • Page 151: Further Configuration And Monitoring

    URTHER ONFIGURATION ONITORING This chapter contains the following topics: General Help Configuration Monitoring Viewing Node Table Information Viewing UDP Statistics...

  • Page 152: General Help

    5: F HAPTER URTHER ONFIGURATION ONITORING General Help Select GENERAL HELP from the Main Menu. The General Help screen appears, providing information on how to control the VT100 bridge management screens. When you are looking at a screen or menu, you can obtain help by typing ? at the prompt.

  • Page 153: Configuration

    Configuration Configuration Downloading Software Upgrades Select CONFIGURATION from the Main Menu. Select SYSTEM from the Configuration menu. Select BOOT/LOADER INFO from the System menu. The Boot/Loader Info screen appears, as shown in Figure 5-1. You use this screen for downloading any upgrades to the bridge's software.
  • Page 154 5: F HAPTER URTHER ONFIGURATION ONITORING Gateway IP Address: Text Field. If you're on a routed network, you will need to enter the IP address of a suitable gateway through which the server can be accessed. Download new software after reboot: Text Field. Enter yes to download the new software.
  • Page 155 Configuration Software does not download The Boot Block User Interface appears, as shown in Figure 5-2, prompting you to change download information. You can do one of two things: Change the download information Enter 1 to update download parameters. The screen for changing download information appears, as shown in Figure 5-3.

  • Page 156: The Permanent Database

    5: F HAPTER URTHER ONFIGURATION ONITORING The Permanent Database Upto 1000 entries in the filtering database can be made permanent. Permanent entries are non-volatile and will not age. Entries can be added, deleted or transferred. Add Permanent Entry Select CONFIGURATION from the Main Menu. Select BRIDGES from the Configuration menu.
  • Page 157 Configuration Port Name: Text Field. The port you want to make the device permanent for. Changes to this field are saved immediately. Reset the bridge for the change to take effect. Total Entries: Display Field. The total number of permanent entries in the filtering database.

  • Page 158: Delete Permanent Entry

    5: F HAPTER URTHER ONFIGURATION ONITORING Delete Permanent Entry Select CONFIGURATION from the Main Menu. Select BRIDGES from the Configuration menu. Select PERMANENT DATABASE from the Bridges menu. Select DELETE ENTRY from the Permanent Database menu. The Delete Permanent Entry screen appears, as shown in Figure 5-5.

  • Page 159: Transfer Permanent Entries

    Configuration Transfer Permanent Entries Select CONFIGURATION from the Main Menu. Select BRIDGES from the Configuration menu. Select PERMANENT DATABASE from the Bridges menu. Select TRANSFER ENTRIES from the Permanent Database menu. The Transfer Permanent Entries screen appears, as shown in Figure 5-6.

  • Page 160: Editing Arp Information

    5-10 5: F HAPTER URTHER ONFIGURATION ONITORING Editing ARP Information ARP Parameters Select CONFIGURATION from the Main Menu. Select NETWORK PROTOCOL from the Configuration menu. Select ARP from the Network Protocol menu. Select PARAMETERS from the ARP menu. The ARP Parameters screen appears, as shown in Figure 5-7.

  • Page 161: Add Arp Entry

    Configuration 5-11 Add ARP Entry Select CONFIGURATION from the Main Menu. Select NETWORK PROTOCOL from the Configuration menu. Select ARP from the Network Protocol menu. Select ADD ENTRY from the ARP menu. The Add ARP Entry screen appears, as shown in Figure 5-8.

  • Page 162: Delete Arp Entry

    5-12 5: F HAPTER URTHER ONFIGURATION ONITORING Delete ARP Entry Select CONFIGURATION from the Main Menu. Select NETWORK PROTOCOL from the Configuration menu. Select ARP from the Network Protocol menu. Select DELETE ENTRY from the ARP menu. The Delete ARP Entry screen appears, as shown in Figure 5-9.

  • Page 163: Changing Tcp Characteristics

    Configuration 5-13 Changing TCP Characteristics Select CONFIGURATION from the Main Menu. Select NETWORK PROTOCOL from the Configuration menu. Select TCP from the Network Protocol menu. The TCP Protocol Settings screen appears, as shown in Figure 5-10. You use this screen for changing operational characteristics of the bridge's TCP (Transmission Control Protocol) software.

  • Page 164: Changing Telnet Characteristics

    5-14 5: F HAPTER URTHER ONFIGURATION ONITORING Changing Telnet Characteristics Select CONFIGURATION from the Main Menu. Select NETWORK PROTOCOL from the Configuration menu. Select TELNET from the Network Protocol menu. The Telnet Protocol Settings screen appears, as shown in Figure 5-11.
  • Page 165 Configuration 5-15 Negotiate display options: Text Field. Causes the local system to display a transcription of the negotiation of virtual terminal options. This negotiation takes place regardless of the value of this parameter, which controls the display of the transcription only.

  • Page 166: Port Queuing

    5-16 5: F HAPTER URTHER ONFIGURATION ONITORING Port Queuing Select CONFIGURATION from the Main Menu. Select SOFTWARE QUEUES from the Configuration menu. The Software Queues screen appears, as shown in Figure 5-12. Do not change the default values of 14 (for MAX SIZE) and 10 (for MAX LIFE).

  • Page 167: Monitoring

    Monitoring 5-17 Monitoring Viewing General Bridge Information Select MONITORING from the Main Menu. Select SYSTEM from the Monitoring menu. Select SYSTEM INFO from the System menu. The General System Information screen appears, as shown in Figure 5-13. You use this screen for viewing general bridge information and statistics.
  • Page 168 5-18 5: F HAPTER URTHER ONFIGURATION ONITORING Available Buffers: Display Field. The number of buffers currently free in the bridge. This number changes over time. System Type: Display Field. The type of bridge. This entry is automatically set. Serial Number: Display Field. The serial number of the bridge, as recorded in the hardware.

  • Page 169: Viewing Node Table Information

    Viewing Node Table Information 5-19 Viewing Node Table Information Node Table By Address Select MONITORING from the Main Menu. Select BRIDGES from the Monitoring menu. Select NODE TABLE/ADDRESS from the Bridges menu. The Node Table By Address screen appears, as shown in Figure 5-14.

  • Page 170: Node Table By Hash Bucket

    5-20 5: F HAPTER URTHER ONFIGURATION ONITORING Node Table By Hash Bucket Select MONITORING from the Main Menu. Select BRIDGES from the Monitoring menu. Select NODE TABLE/HASH from the Bridges menu. The Node Table By Hash Bucket screen appears, as shown in Figure 5-15.
  • Page 171 Viewing Node Table Information 5-21 Total Entries: Display Field. The total number of entries in the filtering database. You can have 4953 entries (additional to the permanent entries). Starting Hash Value: Text Field. The first value of the subset you want to display. Enter a number from 0 to 511 . The default is Ageing Timer: Display Field.

  • Page 172: Viewing The Hardware Configuration

    5-22 5: F HAPTER URTHER ONFIGURATION ONITORING - indicates that the address has not yet appeared at the port as a source address during the current ageing time interval. When the ageing time interval expires, entries set as - are discarded. Viewing The Hardware Configuration Select MONITORING from the Main Menu.

  • Page 173: Viewing Socket Statistics

    Viewing Node Table Information 5-23 Viewing Socket Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select SOCKET STATISTICS from the Network Protocol menu. The Socket Statistics screen appears, as shown in Figure 5-17. You use this screen for checking the status of active socket addresses being used by the bridge.
  • Page 174 5-24 5: F HAPTER URTHER ONFIGURATION ONITORING Proto: Display Field. The type of protocol in use at the local address displayed in the local address column. Recv-Q: Display Field. The number of bytes of data that have been received and are in the socket buffer waiting to be delivered.
  • Page 175 Viewing Node Table Information 5-25 FIN_WAIT_1 which means that the socket is closed and the connection is being closed. CLOSING which means that the local socket has closed and is awaiting remote shutdown acknowledgement. LAST_ACK which means that the remote socket has shut down and is awaiting acknowledgement.

  • Page 176: Viewing Udp Statistics

    5-26 5: F HAPTER URTHER ONFIGURATION ONITORING Viewing UDP Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select UDP STATISTICS from the Network Protocol menu. The UDP Statistics screen appears, as shown in Figure 5-18.
  • Page 177 Viewing UDP Statistics 5-27 Input Packets: Display Field. The total number of UDP packets received by the system. ( udpInDatagrams in the MIB.) No Receive Port: Display Field. The number of UDP packets discarded by the system because there was no application at the destination protocol port.

  • Page 178: Viewing Tcp Information

    5-28 5: F HAPTER URTHER ONFIGURATION ONITORING Viewing TCP Information TCP Data Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select TCP STATISTICS from the Network Protocol menu. The TCP Data Statistics screen appears, as shown in Figure 5-19.
  • Page 179 Viewing UDP Statistics 5-29 duplicate acks: Display Field. The number of frames received where the TCP ACK bit was set and the Acknowledgement number was the same as the previously received ACK. acks for unsent data: Display Field. The number of frames received where the TCP ACK bit was set and the Acknowledgement number is greater than the last byte number in the datastream sent so far.

  • Page 180: Packets Sent

    5-30 5: F HAPTER URTHER ONFIGURATION ONITORING discarded for bad header offset fields: Display Field. The number of packets received that were discarded because the header offset is invalid. discarded because pkt too short: Display Field. The number of frames received and discarded because the data section ends before the length specified by the TCP LENGTH field.

  • Page 181: Tcp Connection Statistics

    Viewing UDP Statistics 5-31 TCP Connection Statistics The TCP Connection Statistics screen appears, as shown in Figure 5-20, after the TCP Data Statistics screen. You use this screen for viewing statistics on a bridge's TCP (Transmission Control Protocol) activity. TCP is a transport-layer protocol of the Internet Protocol suite.
  • Page 182 5-32 5: F HAPTER URTHER ONFIGURATION ONITORING embryonic connections closed: Display Field. The number of connections where a FIN followed a SYN SYN-ACK sequence without an ACK to the SYN-ACK. segments updated rtt: Display Field. The `segment updated rtt' counter. retransmit timeouts: Display Field.

  • Page 183: Viewing Ip Statistics

    Viewing UDP Statistics 5-33 Viewing IP Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select IP STATISTICS from the Network Protocol menu. The IP Statistics screen appears, as shown in Figure 5-21. You use this screen for viewing a statistical summary for all IP activity on the bridge.

  • Page 184: Fragments Received

    5-34 5: F HAPTER URTHER ONFIGURATION ONITORING with size smaller than minimum: Display Field. The number of TCP packets received where the size of the packet is too small. with data size < data length: Display Field. The number of TCP packets received where the actual data is smaller than that specified in the TCP header.
  • Page 185 Viewing UDP Statistics 5-35 packets were fragmented on transmit: Display Field. The number of fragments the bridge transmitted. The FRAGMENTS CREATED subcount (in brackets) shows the number of fragments this bridge created, as opposed to those that it simply forwarded. packets forwarded: Display Field.

  • Page 186: Viewing Icmp Packet Statistics

    5-36 5: F HAPTER URTHER ONFIGURATION ONITORING Viewing ICMP Packet Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select ICMP STATISTICS from the Network Protocol menu. The ICMP Packet Statistics screen appears, as shown in Figure 5-22.
  • Page 187 Viewing UDP Statistics 5-37 destination unreachable: Display Field. The number of ’destination unreachable’ messages sent (output) and received (input). When a node receives an IP packet that it cannot forward to its destination, it sends a ’destination unreachable’ message to the sending node.
  • Page 188 5-38 5: F HAPTER URTHER ONFIGURATION ONITORING time stamp reply: Display Field. The number of ’time stamp reply’ messages sent (output) and received (input). ’Time stamp reply’ is an answer to a ’time stamp’ request. Time information in the ’time stamp reply’ allows the requesting host to estimate the differences between local and remote clocks.

  • Page 189: Viewing Snmp Information

    Viewing UDP Statistics 5-39 Viewing SNMP Information SNMP Statistics Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select SNMP STATISTICS from the Network Protocol menu. The SNMP Statistics screen appears, as shown in Figure 5-23. You use this screen for viewing statistics on the SNMP (Simple Network Management Protocol) activity of the bridge.

  • Page 190: Out Packets

    5-40 5: F HAPTER URTHER ONFIGURATION ONITORING Get Requests: Display Field. The number of GET requests received by the SNMP agent. Get Next Requests: Display Field. The number of GET-NEXT requests received by the SNMP agent. Total Requested Variables: Display Field. The number of MIB variables retrieved by the SNMP agent as the result of GET and GET-NEXT requests.
  • Page 191 Viewing UDP Statistics 5-41 Out Bad Values: Display Field. The number of messages sent by the agent that contained the value ’badValue’ in the error-status field. These messages respond to requests that contain invalid values. Out General Errors: Display Field. The number of messages sent by the agent that contained the value ’genErr’...

  • Page 192: Snmp Authentication Statistics

    5-42 5: F HAPTER URTHER ONFIGURATION ONITORING SNMP Authentication Statistics The SNMP Authentication Statistics screen appears, as shown in Figure 5-24, after the SNMP Statistics screen. You use this screen for viewing access errors detected by the bridge's SNMP agent. All statistic values displayed in this screen reset to zero when the bridge is reset.

  • Page 193: Viewing Arp Tables

    Viewing UDP Statistics 5-43 Viewing ARP Tables Select MONITORING from the Main Menu. Select NETWORK PROTOCOL from the Monitoring menu. Select ARP TABLES from the Network Protocol menu. The ARP Tables screen appears, as shown in Figure 5-25. You use this screen for viewing the ARP table.
  • Page 194 5-44 5: F HAPTER URTHER ONFIGURATION ONITORING Line: Display Field. The line number of the entry. IP Address: Display Field. The 32-bit internet address of a remote node. Ethernet Address: Display Field. The 48-bit physical (MAC) address of the remote node whose IP address is displayed in the IP ADDRESS field.

  • Page 195: Viewing Diagnostic Information

    Viewing UDP Statistics 5-45 Viewing Diagnostic Information Error Log Select MONITORING from the Main Menu. Select DIAGNOSTICS from the Monitoring menu. Select ERROR LOG from the Diagnostics menu. The Error Log screen is shown in Figure 5-26. You use this screen for viewing start-up errors and logged errors.

  • Page 196: Interactive Diags

    5-46 5: F HAPTER URTHER ONFIGURATION ONITORING Interactive Diags Select MONITORING from the Main Menu. Select DIAGNOSTICS from the Monitoring menu. Select INTERACTIVE DIAGS from the Diagnostics menu. The Interactive Diags screen appears, as shown in Figure 5-27. You use this screen for selecting the type of hardware diagnostics you wish to view.

  • Page 197: Clear Error Log

    Viewing UDP Statistics 5-47 Buffer Mem Check: Text Field. This verifies the memory buffers. Each time the test is performed, it will randomly allocate a buffer of memory to verify. Clear Error Log Select MONITORING from the Main Menu. Select DIAGNOSTICS from the Monitoring menu.
  • Page 198 5-48 5: F HAPTER URTHER ONFIGURATION ONITORING DUA1860-0AAA01...

  • Page 199: Problem

    ROBLEM OLVING This chapter contains the following topics: Spot Checks Using The LEDs For Fault Diagnosis Correcting Problems Removing And Replacing Equipment Spares What To Do Next...

  • Page 200: Spot Checks

    It is good practice to carry out regular checks of your LinkBuilder MSH equipment. Check the following: LEDs Press the LAMP TEST button, on the LinkBuilder MSH's Display Panel. All yellow LEDs should light continuously and all bi-color LEDs should flash red/green alternately. Cabling Check that all external cabling connections are secure and that no cables are pulled taut.

  • Page 201: Using The Leds For Fault Diagnosis

    Using The LEDs For Fault Diagnosis Using The LEDs For Fault Diagnosis The LEDs on the front of the module indicate bridge activity and faults: PWR (Power) Green on - Normal: power present, self-test completed successfully and bridge operating normally. Green flashing - Self-test is in progress (this lasts about one second).

  • Page 202: Correcting Problems

    6: P HAPTER ROBLEM OLVING Correcting Problems By working through this section, you should be able to isolate faults or find some possible causes and recommended actions. Network Problems Symptom: Network communication problems. Action: Check the cabling in your network and that it meets the IEEE standard for cabling.

  • Page 203: Port Problems

    Remove the bridge module from the LinkBuilder MSH chassis, and reinstall it. It is unlikely that any problems will result from this operation. For more information on possible problems, see Removing And Replacing Equipment on page 6-8.

  • Page 204: Collision Problems

    6: P HAPTER ROBLEM OLVING Collision Problems Symptom: Excessive collisions on an Ethernet port. Action: Check that your network is not too long or too large. Check that there are not too many repeaters on your network. Check that there are not too many users on a single Ethernet. STAP Problems Symptom: Spanning Tree problems.

  • Page 205: Snmp Problems

    Symptom: The bridge does not respond to the keyboard, or freezes in operation. Action: Press [Ctrl] + [P] to return to the management module, and reset the MSH chassis slot that the bridge is in (slot reset). Remove and install the bridge into the LinkBuilder MSH chassis. DUA1860-0AAA01...

  • Page 206: Removing And Replacing Equipment

    OLVING Removing And Replacing Equipment Inserting additional modules or a second Power Supply Unit into an active LinkBuilder MSH, known as hot insertion, should not cause any damage to your equipment. However, the following points should be noted: Packets of data passing through the unit at the time of insertion can be corrupted.

  • Page 207: Spares

    We recommend that you have one spare module or Power Supply Unit for every ten in use. In the unlikely event that you should have problems with the LinkBuilder MSH, you should swap the faulty item with a spare. This allows you to continue operation and may also help in singling out a fault, if the replacement solves the problem.

  • Page 208: What To Do Next

    6: P HAPTER ROBLEM OLVING What To Do Next If any of your LinkBuilder MSH equipment fails to operate correctly, contact your supplier with the following information before returning the equipment: Serial Number Revision Number A brief description of the fault For modules, the Serial Number and Revision Number are printed on the circuit board.

  • Page 209: Link

    ETTINGS The LinkBuilder MSH 4 Port Ethernet Bridge Module has a link, LK1, for resetting its configuration to default values, see Figure A-1. Figure A-1 The Location Of The Link WARNING: This method of resetting the module has the same effect as initializing NVRAM via the VT100 management interface.
  • Page 210 PWR LED flashing), remove it from the LinkBuilder MSH chassis. 5 Change the link to the normal position, see Figure A-3. Figure A-3 The Link In The Normal Position 6 Install the module into the LinkBuilder MSH chassis. The module is now reset to its default settings. DUA1860-0AAA01...

  • Page 211: Technical Information

    ECHNICAL NFORMATION The LinkBuilder MSH 4 Port Ethernet Bridge Module conforms to the following standards: Electrical IEEE 802.3, ISO DIS 8802/3 Safety EN 60950 (BS 7002) UL 1950 CSA 222 #950 ECMA 97 Vfg 243 ’B’ EN 55022 A FCC 20780 15J Level A...

  • Page 212: Mib

    B: T HAPTER ECHNICAL NFORMATION IETF Bridge MIB (RFC 1286) RFC 1213 (MIB II) and RFC 1229/1239 extensions DUA1860-0AAA01...

  • Page 213: Support

    3Com provides easy access to technical support information through a variety of services. This appendix describes these services. On-line Technical Services 3Com offers worldwide product support seven days a week, 24 hours a day, through the following on-line systems: 3Com Bulletin Board Service ®...

  • Page 214: Ask3Com On Compuserve

    3Com Corporation’s interactive fax service, 3ComFacts , provides data sheets, technical articles, diagrams, and troubleshooting instructions on 3Com products 24 hours a day, seven days a week. Within this service, you may choose to access CardFacts for adapter information, or NetFacts for network system product information.

  • Page 215: 3Com Documentation On Cd-Rom

    3Com Documentation on CD-ROM NetFacts provides data sheets and technical articles on 3Com Corporation’s hub, bridge, router, terminal server, and software products. Document 8888 provides you with an index of system product documents. Call 3ComFacts using your touchtone telephone. International...

  • Page 216: Support From Your Network Supplier

    If you are unable to receive support from your network supplier, technical support contracts are available from 3Com. In the U.S. and Canada, call (800) 876-3266 for customer service. If you are outside the U.S. and Canada, contact your local 3Com sales office to find your authorized service provider. DUA1860-0AAA01...

  • Page 217: Returning Products For Repair

    (1) (408) 492 1790 Returning Products for Repair A product sent directly to 3Com for repair must first be assigned a Return Materials Authorization (RMA) number. A product sent to 3Com without an RMA number will be returned to the sender unopened, at the sender’s expense.
  • Page 218 .C-6 C: T PPENDIX ECHNICAL UPPORT DUA1860-0AAA01...
  • Page 219 NDEX bridge information, viewing 5-17 Numerics bridge menu map 2-6 bridge module 1-3 3ComBBS C-1 connections 1-3, 2-30 3ComFacts C-2 information 5-17 installation and removal 1-31 LEDs 1-5 logging off 2-28 access, user 4-16 logging on 2-17, 2-30 active loops 1-16 management 1-7 Add ARP Entry screen 5-11 management interface 2-3...
  • Page 220 Index Checking for valid network connection 2-38 LEDs, cabling and modules 6-2 Edit User Accounts screen 2-22 port activity 4-8 editing user access 4-16 ARP information 5-10 Clear Error Log screen 5-47 operator accounts 2-22 Cold Start trap 2-47 permanent database 5-6 collision problems 6-6 enabling communication, with another bridge...
  • Page 221 2-28 Host Filter Info screen 3-27 logging on host filtering table 3-27 bridge module 2-17, 2-30 saving changes 3-29 LinkBuilder MSH 2-12 host names, assigning 2-36 requirements 2-30 host table 2-36 Login History screen 4-16 host-to-host filtering 1-23...
  • Page 222 Index operator accounts editing 2-22 setting up 2-18 related standards B-1 Operator Accounts screen 2-20 remote access 2-31 Operator Login screen 2-17 remote bridge connection 2-30 remote bridges 1-9 Remote Connect screen 2-43 removal 1-31 removing and replacing equipment 6-8 packet statistics 5-36 replacing the fuse 6-9 performance problems 6-5...
  • Page 223 3-13 IP Host Table 2-36 IP address 2-31 IP Statistics 5-33 IP address / host name pairs 2-36 LinkBuilder MSH Address Table 2-16 MIB view 2-46 LinkBuilder MSH Logon 2-13 multicast-to-port filtering 3-18 LinkBuilder MSH Main Banner 2-12...
  • Page 224 Index STAP 1-16 problems 6-6 root bridge 1-17 viewing starting a Telnet session 2-42 ARP tables 5-43 static routes 2-33 diagnostic information 5-45 configuring 2-33 error log 5-45 Static Routes screen 2-33 general bridge information 5-17 subnet mask 2-31 hardware configuration 5-22 suspending a Telnet session 2-45 host filtering table 3-27 System Information screen 2-24...
  • Page 225 ADIO REQUENCY NTERFERENCE TATEMENTS FCC Statement This equipment has been tested with a class A computing device and has been found to comply with part 15 of FCC Rules. Operation in a residential area may cause unacceptable interference to radio and TV receptions requiring the operator to take whatever steps are necessary to correct the interference.
  • Page 226 Information To The User If this equipment does cause interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Reorient the receiving antenna.
  • Page 227 Spare parts and spares kits 90 days If a product does not operate as warranted during the applicable the warranty period, 3Com shall, at its expense, correct any such defect by repairing the defective product or part or, at its option, by delivering to Customer an equivalent product or part to replace the defective item.
  • Page 228 WARRANTIES EXCLUSIVE: If a 3Com product does not operate as warranted above, Customer's sole remedy shall be repair, replacement, or refund of the purchase price paid, at 3Com's option. THE FOREGOING WARRANTIES AND REMEDIES ARE EXCLUSIVE AND ARE IN LIEU OF ALL OTHER...

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