Managing the Maximum Transmission Unit, Fragmentation

Managing the Maximum Transmission Unit

Introduction

The maximum transmission unit (MTU) value specifies the maximum size of the datagram that a given access server port accepts. The range is 64 to 1500 bytes. The default is 1500 bytes.

Changing the MTU

You can change the MTU value using the SET/DEFINE/CHAGE PORT n MTU command. If you use the SET or CHANGE command, the new value does not affect an existing SLIP connection.

MTU Change Example:

The following example makes the access server compatible with attached hosts that have fixed MTU values other than 1006 bytes:

Local> DEFINE PORT 4 SLIP MTU 500

Relationship of the TCP Maximum Segment Size and the MTU

An attached host announces the TCP maximum segment size (MSS) at connection time. The MSS specifies the largest fragment of a datagram that the attached host is willing to receive. The MSS is normally based on the MTU of the network connection as recommended by RFC 879.

The MSS should always be smaller than the MTU value. The TCP and IP headers account for the difference between the two values.

Fragmentation

When the TCP MSS announced by the SLIP host exceeds the MTU on the SLIP line, IP fragmentation occurs. Therefore, an MSS value that greatly exceeds the MTU causes excessive fragmentation and downgrades performance.

Setting the MTU adjusts the point at which IP fragmentation occurs when sending datagrams. Setting the MTU also adjusts the maximum receive unit (MRU) packet size. Since the access server considers packets larger than the MTU as framing errors, it discards these packets.

Configuring and Managing SLIP Ports 15-7

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HP NetRider manual Managing the Maximum Transmission Unit, Changing the MTU, Fragmentation, MTU Change Example

Contents

Software and Version Revision/Update Information Digital Equipment Corporation 199 7. All rights reserved Contents User Interface Managing Load Hosts Configuring LAT Characteristics Vii TCP/IP Network Characteristics Managing AppleTalk Configuring Basic Device Characteristics Configuring Modem Signals Configuring and Managing Interactive Devices Xiii Configuring and Managing LAT Services Configuring LPD Printers Configuring and Managing Slip Ports Configuring for Snmp Access Configuring and Managing 3270 Terminal Emulation TN3270 Configuring and Managing Point-to-Point Protocol PPP Ports Managing IPX Managing Dial Services Managing Access Server Security Xxiii Accounting Glossary Index Page Purpose Using This ManualPreface Overview Text ConventionsConvention Meaning Uppercase Associated Documents How to Order Additional Documentation To Order ContactDigital Equipment Corporation FAX Online ServicesCorrespondence Documentation CommentsPage Chapter Dnas Management IntroductionThis Chapter Default Settings Configuration Tasks for System AdministratorsConfiguration Tasks To Configure Refer to Management Tasks for System Administrators System Management TasksTo Manage Refer to Accessing Online Help User TasksLocal Help Tutorial Storage of Configuration Settings and Changes in Memory Power LossMemory Types Nvram Commands to Display and Change Configuration SettingsTypes of Commands That Operate on Configuration Settings Reference Chapter Management Tools Access Server Commands Levels of Access Server CommandsCommand Provides Access to Commands to Enable Level Disable Command Definitions Command ResultUser Groups Local SET Server Privileged Password Privileged CommandsExample Enabling Privileged Commands Example Changing the Privileged Password Help Help Tutorial CommandHelp Command Example Accessing Online Help Information Local Show Server Example Show Server CommandConsole Port Displaying Port Parameters Communications Utilities for Remote Console Sessions Features of the Remote Console PortRemote Console Port Description Network Control Program NCP OpenVMS Utility Terminal Server ManagerUsage Considerations Use of SET HOST/MOP from a DECnet/OSI OpenVMS Node $ MCR NCP NCP Connect Node Shrimp Service Password Fedcba Badcfe Use of CCR from an Ultrix DECnet Node Telnet Remote Console CharacteristicDescription Characteristics of the Telnet Remote Console Port Access Server Manager FunctionsRelated Information Page Chapter User Interface Command Groups and Menus Step Action Using Command GroupsCreating a Command Group Example Defining a Command Group Executing a Command Group Displaying a Command GroupPurging a Command Group Example Show Menu Command Using MenusDisplaying a List of Enabled Menus Entering Menu Mode Menu Windows Assigning a Default Menu to a PortExample Assigning a Default Menu Local Define Port 2 Default Menu Hosts Figure Windows on Access Server Menus Local Change Menu Services from Main Defining MenusMain Menu Defining Menu Choices Main Menu Display Example Sample Definition of a Menu Selection Displaying a Selected Menu Example Displaying a Menu Definition Using Menus to Set Up a Captive PortExiting from a Menu Displaying a Menu Definition Example Commands to Purge Entire Menus and Menu Lines Purging Menu Lines and Entire MenusLocal Purge Menu Main Line Local Purge Menu Hosts Chapter Managing Load Hosts ∙ DSV$CONFIGURE ∙ Dsvconfig Load Host Procedures Backward Compatibility of DSV$CONFIGURE Executing DSV$CONFIGUREDefining Symbols Server ADD CommandExample Starting DSV$CONFIGURE and Displaying Help Command Description Component Modify and SET Commands Delete CommandExample DSV$CONFIGURE ADD Command Example List Command for DSV$CONFIGURE List and Show CommandsConnect and USE Commands Example Delete Command for DSV$CONFIGURE Local CTRL/D Local Show User Context-Sensitive Help for DSV$CONFIGURE Dsvconfig Menu DECserver Configuration Procedure IP Address Configuration Via Bootp Using a BOOTP/TFTP Server Remote Connection Password Upline Dumps with BOOTP/TFTP Hosts Upline DumpingUpline Dumps with MOP Hosts For TSM Users Terminal Server Manager TSMPage Chapter Initializing the Access Server Do This Preparing LAT Services for Initialization Preparing Telnet Listeners for Initialization Disabled Login Methods Initializing the Access ServerUsing the Initialize Command Default Mode for the Initialize Command Updating Flash RAM Specifying an Image Name When InitializingSpecifying a Delay Value with Initialize Specifying Initialization from a Load Host Test Performs Using the Diagnose Option with InitializeSpecifying the Disable Option with Initialize Initialize Diagnose Option Tests NCP Reference Using NCP to Initialize the Access ServerNCP Initialization Commands NCP Initialization Description Commands Reference Booting from the NetworkDetermining Boot Protocols Loading the Software Image Procedure Booting Using Console Commands Option Definition Associated Options Boot Command Options Option Definition Associated Options Page Chapter Configuring LAT Characteristics Characteristic Default Range Refer to Section LAT CharacteristicsPreparing to Change LAT Characteristics LAT Characteristic Summary Queue Limit Service Groups EnabledDisabled Passcheck Displaying LAT Characteristics Command To UseLAT Characteristics Display Example Configure Announcements Example Announcements Characteristic Decreasing the Circuit Timer Circuit Timer CharacteristicChanging the Circuit Timer Increasing the Circuit Timer Removing an Identification String Identification CharacteristicIdentification String in a Login Procedure Display Changing the Server Identification String Local Change Server Keepalive Keepalive Timer CharacteristicKeepalive Timer Default Values Keepalive Timer Example Local Change Server Multicast Timer Multicast Timer CharacteristicMulticast Timer Default Values Changing Multicast Timer Values Example Local Change Server Name Printing Access Server Name CharacteristicDefault Access Server Name Changing the Access Server Name Node Limit Characteristic Changing the Access Server Node LimitLocal Change Server Node Limit Local Change Server Number Access Server Number CharacteristicAccess Server Number Values Changing the Access Server Number Local Change Server Passcheck Enabled Passcheck CharacteristicChanging the Passcheck Characteristics Passcheck Characteristic Example Local Change Server Queue Limit None Queue Limit CharacteristicSpecial Queue Limit Values Changing the Queue Limit Local Change Server Retransmit Limit Retransmit Limit CharacteristicChanging the Retransmit Limit Characteristic Retransmit Limit Values Datagram Name Description Responder CharacteristicAccess Server Mapping Datagram Types Local Change Server Responder Enabled Changing the Responder Characteristic Changing Service Groups Examples Service GroupsViewing Service Groups Changing Access Server Service Groups Chapter TCP/IP Network Characteristics TCP/IP Network Characteristics Alternative Learning IP Information Configuring the Internet Address and Subnet MaskSetting the Internet Address Tasks Internet Address Class Default Subnet Mask Setting an Internet Subnet Mask Configuring the Internet Address and Subnet Mask Displaying the Internet Address and Subnet Mask Internet Address and Subnet Mask Display ExampleLocal Show Internet Internet DNS Character Display Example Configuring Domain Name System DNS CharacteristicsDisplaying DNS Characteristics Local Show Internet Name Resolution DNS Field Description Local Show Internet Name Resolution Counters Displaying the DNS CountersDNS Counter Display Example Configuring and Using Default Name Resolution Domain Example Configuring the Default Name Resolution Domain Local Connect SALES.REVENUE Using Trailing Dots Changing the Retry Limit Changing the Name Resolution ModeName Resolution Modes Changing the Time Limit Configuring a Root Name Server Configuring a List of Commonly Used Internet HostsConfiguring a List of Internet Name Servers If Using a Name Server Name Resolution and Gateways Configuring a Name Server for a Different Domain Pass Description Assigning DNS Server Addresses Automatically Displaying a List of Gateway Addresses Configuring a List of Internet Gateway AddressesConfiguring a Default Gateway Default Gateway Definition Example Subnet Definition Through a Specific Gateway Example Defining Networks Available Through a Specific GatewayDefining Subnets Available Through a Specific Gateway Defining Hosts Available Through a Specific Gateway Sample List of Internet ARP Entries Configuring a List of Internet ARP EntriesDisplaying the List of Internet ARP Entries Defining an ARP Entry Disabling the Timer Setting the TCP Keepalive TimerWhat the Timer Does Setting the Timer Local Change Internet TCP Keepalive Retry Displaying Timer CharacteristicsTimer Characteristics Display Retry Set Example Local Show Internet Counters Using the Show CommandDisplaying the Internet Counters Internet Counters Display Example Bytes Data Retransmitted Total number Internet Counter Display Fields Field Description 24 TCP/IP Network Characteristics Learning IP Information From a Bootp Server Bootp Server ConfigurationLearning Operation Local Define Internet Address None Setting Up IP Configuration LearningLocal Define Internet Enabled Local List Internet Bootp and Dhcp Differences Using a Bootp Server Using a Dhcp ServerLearning IP Information From a Dhcp Server Dhcp Client Operation IP Address Assignment Dhcp Proxy Operation Enabling and Disabling Dhcp Displaying the Dhcp SettingConfiguring Default Values To Do This Use This Command Operation What Is Wins Autoconfigure?Assigning Wins Server Addresses What Does Wins Do? Wins Display Example Displaying Wins CharacteristicsAssigning Wins Addresses Wins Address Example Field Description Page Chapter Managing AppleTalk Overview Enabling AppleTalk Configuring AppleTalk on an Access ServerLocal Define Appletalk Enabled AppleTalk Address Format Local Define Appletalk address Cache size n Setting AppleTalk Address Cache SizeLocal Define Appletalk Disabled Disabling AppleTalk Configuring AppleTalk on an Access Server Fields in the AppleTalk Characteristics Display Displaying AppleTalk CharacteristicsCommands Displaying AppleTalk Characteristics Example Fields in the AppleTalk Counters Display CommandDisplaying AppleTalk Counters Displaying AppleTalk Counters Example DDP NBP RtmpZIP Aarp Values Field Value Description Displaying AppleTalk StatusDisplaying AppleTalk Status Example Fields in the AppleTalk Status Display AppleTalk is fully operational Local Show Appletalk Routes Displaying AppleTalk RoutesDisplaying AppleTalk Routes Example Fields in the AppleTalk Routes Display Field Value Description Local Show Appletalk ARP Entries Displaying AppleTalk ARP EntriesDisplaying AppleTalk ARP Entries Example Fields in the AppleTalk ARP Display Field Value Description Page Chapter Configuring Basic Device Characteristics Configuring Basic Device Characteristics Basic Device Characteristic SummaryCharacteristic Default Allowed Refer to Values Section Speed LongbreakLogout Longbreak Output Flow Parity Displaying Basic Device Characteristics Displaying Port Characteristics ExampleLocal Show Port Local Define Port 5 Access Remote Configuring the Access CharacteristicDefining the Access Characteristic Example Characteristic Device Type Examples Matching the Port and Device Characteristics Autobaud SettingsSetting For These Devices Character Size Parity Setting Check Performed Per Character Example Changing the Parity Settings Example Setting the Stop Bits for a DeviceExample Changing the Port Speed Local Change Port 5 Type Hardcopy Device TypesDevice Type Applies to Example Changing the device Type ∙ XON/XOFF ∙ DSR ∙ CTS Configuring the Flow Control CharacteristicWhen to Use Flow Control Types Example Enabling XON/XOFF Flow Control Example Enabling DSR Flow ControlExample Enabling CTS Flow Control Example Enabling output Flow Control Flow Control DirectionExample Disabling Flow Control Example Enabling Input Flow Control Example Enabling Dsrlogout Specifying the Automatic Logout CharacteristicsSpecifying Dsrlogout Specifying Longbreak Logout Example Enabling Inactivity Logout Specifying the Inactivity TimerExample Changing the Inactivity Timeout Period Specifying Inactivity Logout Chapter Configuring Modem Signals Port Configuration DTE/DCE Device Configuration Network Access Server Modem Signals Supported Type Determining the Supported Modem SignalsAccess Servers and Modem Control Access Server Types and Supported Modem Signals Set Modem Signals Description Types of Modem SignalModem Signal Description Dsrs Specifying Modem Control and Signal Control Logging Out the Port with Dsrlogout or Longbreak LogoutComputer Interface Example Enabling Signal Control Local Define Port 5 Modem Control Enabled Local Logout PortExample Enabling Modem Control Specifying Signal Select Determining When to Use a Signal SetExample Enabling Signal Select Specifying Signal Check Example Enabling Signal CheckLocal Change Port 7 Signal Check Enabled Local Change Port 3 Dtrwait Enabled Specifying DtrwaitEnabling Dtrwait Example Specifying Ring Specifying Alternate Speed Specifying Dialup Modem Control Sample Modem ConfigurationsConfiguring a Dial-In Modem on a Full Modem Control Server Configuring a Dial-In Modem on a Modem Control Server Configuring a Dial-Out Modem on a Full Modem Control Server Configuring a Dial-Out Modem on a Modem Control Server Establishing a Connection Modem Control Sequences Response to Momentary Loss of CTS Disconnecting Signal Control Configuring DTR and DSR SignalsPort Characteristic Effects on the DTR and DSR Signals Enabled Characteristic DTR and DSR Actions Dtrwait Dsrlogout Signal Control Signal CHECK, DtrwaitCheck For More Information Chapter ∙ Managing Users ∙ Managing Sessions Configuring an Interactive Device for LAT Sessions Configuring an Interactive Device for LAT Sessions Configuring LAT Group Codes for Interactive Devices Sample Network Configuration Local Change Port 5 Autoconnect Enabled Specifying AutoconnectExample Enabling Autoconnect Example Disabling Autoprompt Specifying the Default ProtocolLocal Change Port 5 Autoprompt Disabled Specifying Autoprompt Example Enabling Queuing on a Port Configuring Port QueuingSpecifying Failover Example Disabling Port Failover Option Displays Entries For Displaying Access Server Queue Entries Example Remove Queue Removing Entries from the Access Server QueueShow Queue ALL Display Example Effect on the Queue Local Change Port 5 Remote Modification Enabled Configuring Port Characteristics Configuring a Device on Port 6 for Internet Hosts Example Configuring an Interactive Device for Telnet Sessions Reference Benefits and Restrictions Summary Configuring a Session Management TD/SMP TerminalHow to Configure Local Change Port 2 Multisessions Enabled Command Descriptions Local Mode Command Restrictions During Session Management Logging In with Multisessions Local Change Port 5 ON-DEMAND Loading Enabled Configuring On-Demand Loading for Asian TerminalsOn-Demand Loading Configuration Example Disable Switch Character Buffer Size Configuring for Block-Mode Terminals Profile Characteristics Specifying the Telnet Client Session ProfileProfiles Types Profiles Session Character Binary Characteristics Characters Terminal Type Switch Example Specifying Echo Characteristics Modifying Telnet Session CharacteristicsSpecifying Echo Characteristics Specifying the Binary Characteristic Mapping Keyboard Characters to Telnet Functions Specifying Character Size Function Description Default Telnet Keymapping FunctionsLocal Change Port 5 Telnet Client AO None Example Disabling Autoflush Specifying AutoflushSpecifying Autosynch Specifying Telnet Client Newline Examples Enabling Flow Control Local Change Port 5 Telnet Client Flow Control DisabledSpecifying Flow Control Example Specifying Telnet Client Newline Specifying the Switch Character Example Configuring Message VerificationSpecifying Message Verification Local Change Port Telenet Client Terminal VT321 Example Configuring Switch CharacterSpecifying a Preferred Terminal Type Example Specifying Terminal Type Managing Access Server User Accounts Minimal Setup for Local User AccountsOptional Setup for Local User Accounts SHOW/LIST/MONITOR Useraccount Display Authorization Profile Information Service Type User Access Service Types and Access LevelsService Permissions Access Service Type Description Command Description Variables Comments Clause User Account Command Parameters Variable Definition Access Command Variables Providing a Contact Name and Access Server Location Specifying Preferred Service for LAT or Telnet ResourcesManaging Users For the Telnet Protocol Example Enabling a Preferred Telnet ServiceExamples Configuring Port Username Specifying the Port Username Specifying Keys to Switch Between Sessions Example Defining Keys as SwitchesLocal Change Port 5 Forward Switch F Backward Switch B Defining the Break Key Specifying a Key to Switch to Local Mode Example Disabling Broadcast Messages Example Configuring a Key as a SwitchExample Disabling a Local Switch Specifying Broadcast Specifying Loss Notification Example Broadcast ALLExample Disabling Loss Notification Example Disabling Verification Specifying Message CodesSpecifying Verification Specifying Lock Local Show Users Example Configuring LockDisplaying Information About the Users Example Show Users Display Specifying User Groups SHOW/LIST/MONITOR Users Display HeadingsHeading Description Local SET Port Groups Example Assigning User Groups Initiating a Session to an Internet Host Initiating a Session to a LAT ServiceExample Initiating a Session to a LAT Service Managing Sessions Local Send Telnet AO Sending Telnet Functions to a Remote Telnet ServerExample Initiating a Session with an Internet Host Local Open Sales Local Telnet Sales Local Change Port 5 Session Limit Controlling the Number of SessionsExample Changing the Server Session Limit Local Change Server Session Limit Displaying Session Information Example Show Sessions DisplayLocal Show Sessions Port 1,2 SHOW/MONITOR Sessions Display Fields Local Show Port 14 Session 1 Status Displaying Session CharacteristicsLocal Show Port 4 Sessions 1 Characteristics Displaying Session Status SHOW/MONITOR Port Sessions Status Display Fields Flow Control commands to enable Terminating Sessions Page Prerequisites Chapter Configuring and Managing LAT Services Configuration Parameters Configuring a Port to Offer a LAT Service Configuring Access to a LAT Service Assigning a Service NameEnabling Announcements Port Naming Guidelines Assigning an Identification StringAssigning a Port Name Example Clearing the Identification String Example Clearing the Service Password Specifying the Service PasswordPassword Limit Example Assigning a Service Password Example Configuring a PC As a Terminal and LAT Service Configuration of Specific Types of Devices As LAT Services Configuring a Computer As a LAT Service Example Configuring a Computer As a LAT Service on PortLocal Define Port 2 Dedicated None Dialup Enabled Dsrlogout Example Configuring a Dial-In and Dial-Out Modem Configuring a Modem As a LAT Service Privileges for Running Latcp Configuring a Printer As a LAT ServiceSetting Up a LAT Remote Print Queue on an OpenVMS Host Example Configuring a Printer As a LAT Service on Port LTLOAD.COM Creating a Logical Device to Access a Printer ServiceConfiguring a Logical Device to Connect a Specific Port Using a Remote Printer Command File Setting Up a LAT Remote Print Queue on an Ultrix System Configuration of Specific Types of Devices As LAT Services Configuring a Printer with Unannounced Availability Configuring a Printer with Unannounced Availability More Examples Local Connect LAT Adevice Destination PORT5 Verifying the LAT ServiceProblem Solving Example Verifying the LAT Service Displaying Services Characteristics Displaying Information About a Service Example Show Service Characteristics Display SHOW/LIST/MONITOR Service Characteristics Display FieldsLocal Show Service Printer Characteristics Displaying Services Status Example Show Service Status Display SHOW/LIST/MONITOR Service Status Display HeadingsLocal Show Service Develop Status Displaying Services Summary Example Show Service Summary Display SHOW/LIST/MONITOR Service Summary Display HeadingsLocal Show Services ALL Summary Page Chapter Configuring and Managing Telnet Servers Local Define Port 4 Dedicated None Dsrlogout Disabled Flow Sample Device ConfigurationsConfiguring a Printer for Access Through a Telnet Listener Local Define Port 4 Access Remote Autobaud Disabled Break Example Configuring a Dial-Out Modem Configuring a Computer for Access Through a Telnet ListenerConfiguring a Modem for Access Through a Telnet Listener Sample Device Configurations 890-1234 Local Change Telnet Sample Configuration Configuring Personal Computer Access to a PrinterSwitching Modes Local Change Port 5 Interrupts Enabled Break Local Setting User Priority for Devices Using Dynamic Access Partner Guidelines Configuring a File Transfer Partner Characteristic Setting Configuring a Remote Print QueueConfiguring a TCP/IP Remote Print Queue on an Ultrix System Printer Port Telnet Server Characteristics # lprsetup Configuring a TCP/IP Remote Print Queue on a Unix System Configuring a Telnet Listener Event Indication Description Configuring Telnet Server Session CharacteristicsMapping Event Indications to Keyboard Characters Event Indications Local Change Port 5 Telnet Server Character Specifying Newline Characteristics Local Change Port 5 Telnet Server Transmit Character Size Example Setting Character Size in a Specific Direction Displaying Telnet Listeners Managing Your Access Server As a Telnet Listener NodeDisplaying Telnet Server Characteristics Example Show Port Telnet Server Characteristics Display Removing a Telnet Listener Removing One of Many Devices Assigned to a Telnet ListenerExample Removing a Telnet Listener Reassigning a Port Example TCP Messages to Poll Client User Location Data Supplying User Location Data to Telnet Servers Example Configuring Raw TCP Configuring a Raw TCP ListenerWhen To Use Raw TCP Configuring Raw TCP Example Raw TCP Display Displaying Raw TCP Characteristics Chapter Configuring LPD Printers This File Contains LPD OperationSupported File Types Control and Data Files LPD Operation Operation If Printing From Then This Host Configuring LPDConfiguring Remote Hosts Associating a Printer With a Port Characteristic Description Setting Port Characteristics Local Show Printer ALL Printer Configuration ExampleDisplaying Printer Characteristics Printer Display Example Speedy Local Show Printer Speedy Status Chapter Configuring and Managing Slip Ports Configuring and Managing Slip Ports Packet Forwarding to and from Slip Hosts Network Configuration Containing Slip Hosts Displaying Slip Characteristics Displaying Slip Characteristics ExampleLocal Show Port 5 Slip Characteristics Local Change Port Slip Host Address Managing Internet Addresses for Slip HostsAssigning a Host Internet Address Radius Specified Slip Host Address How a Port Automatically Obtains the Slip Host Address Fragmentation Managing the Maximum Transmission UnitChanging the MTU Relationship of the TCP Maximum Segment Size and the MTU Define Port Default Protocol Slip Dsrlogout Enabled Example Configuring a PC As a Terminal and Slip Host Configuring a Device As a Dedicated Slip Host Configuring a Dedicated Slip Port Configuring a Dial-In Modem for Use with a Slip Host Prerequisites Establishing Terminal Sessions with a PC Establishing a Slip Session Enabling a Slip Session from the PCAfter Making a Connection Automatic Cslip Compressed SlipEnabling Cslip Disabling Cslip Local Show Port 5 Slip Counters Displaying Slip CountersShow Port Slip Counters Display Slip Counters Display Fields Disable Slip Example Local Change Port 2 Slip DisabledDisabling Slip Page Chapter Configuring for Snmp Access Supported Snmp Operations Supported Snmp FeaturesSupported Specifications Snmp Community Names Supported MIBs Supported MIB VariablesMIB Description Supported Management Information Base Variables Displaying Information About Snmp Configuring the Access Server for Snmp AccessDefault Community Name Public Enabling and Disabling Snmp One IP Address for a Community Name Configuring a Community Name for Access by Any NMSConfiguring a Community Name with an Address Example Configuring Community Names for Access by Any NMS Configuring Community Names to Send Trap Messages Example Configuring Snmp Trap MessagesThis Event Occurs When Removing Community Names Sample Snmp ConfigurationLocal Clear Snmp Community Server Trap Disabled Disabling Trap Messages for a Community Name Local Change Snmp Community Server Address ANY Removing an Address from a Community NameExample Removing the Community Name Internet Address Local Clear Snmp Community Bugs Configuring the NMS Chapter Managing the Access Server Checking LAT Service Accessibility Managing Your Access Server As Part of the LAT NetworkDistributing Devices on Access Servers Controlling the Number of Known Service Nodes Local Show Node Peach Status Reducing Memory UsageViewing LAT Node Status Information Example Show Node Status Display SHOW/LIST/MONITOR Node Status Display Fields Viewing LAT Node Counters Information Example SHOW/LIST/MONITOR Node Counters Display TSHOW/LIST/MONITOR Node Counters Display FieldsLocal Show Node Peach Counters Field Description Ports with Limited View Viewing LAT Node Summary Information Example Node Summary Display Node Summary Display FieldsLocal Show Node ALL Summary Local Change Server Prompt Engineering Displaying Information About the Access ServerDisplaying Access Server Counters Specifying the Prompt Local Show Server Counters Example Show Server Counters DisplaySHOW/LIST/MONITOR Server Counters Display Fields Ethernet Data Link Counters Field Description Field Description Field Description LAT protocol Counters Displaying Access Server Status Example Show Server Status DisplayLocal Show Server Status MOP Field Description Memory used for storing service and node Field Description Field Description Displaying Access Server Summary Information Example Show Server Summary Display SHOW/LIST/MONITOR Server Summary Display FieldsLocal Show Server Summary Checking Port Status and Counters Displaying Port Characteristics Example Show Port Characteristics Display Local Show Port 1 CharacteristicsDisplaying Port Counters Example Show Port Counters Display SHOW/MONITOR Port Counters Display FieldsLocal Show Port 1 Counters Local Show Port 1 Status Displaying Port StatusExample Show Port Status Display SHOW/MONITOR Port Status Display Fields Field Description Displaying Port Summary Example Show Port Summary DisplayLocal Show Ports ALL Summary SHOW/LIST/MONITOR Port Summary Display Fields Configuring and Managing 3270 Terminal Emulation TN3270 Definition Supported Ascii Terminals Definition and Description of a Keyboard Map KeyboardsServer-Specific Keyboard Maps Setting Up an Ascii Terminal Configuring Basic 3270 Terminal Emulation Specifying the Type of Ascii Terminal Used for Emulation Terminal Setup ParametersTerminal Model Setup Parameters Indicating the 3270 Model Number Entering and Editing Data Connecting to an IBM HostStatus Line Indicator IBM Host Communications Message Description Status Line Messages Status Line Indicator Display Local Show TN3270 Terminal Default Server-Wide Terminal Types and Keyboard MapsDisplaying and Customizing Keyboard Maps Server-Wide Keyboard Maps Customization Local Show TN3270 Keymap VT220 Default Server-Wide Terminal Type and Keyboard MapsPredefined Terminal Type Default Keyboard Map Defining New Server-Wide Terminal Types and Keyboard Maps Local Change TN3270 Keymap Newkeys Clear CTRL/W Customizing Server-Wide Keyboard MapsRules for Customizing Keyboard Maps Local Change TN3270 Terminal PC100DCA Keymap Newkeys Local Show TN3270 Terminal VT100, Ansi Selecting and Customizing Keyboard Maps for a PortKeyboard Map and Terminal Type Predefined Terminal Device Associated Keyboard Map Customizing a Default Keyboard Map for a Port Local Change Port 2 TN3270 Terminal VT420Local Change Port TN3270 Keymap Newline Ctrl/J Following example shows a partial display of a keymap Example Show Port TN3270 Keymap Command SHOW/SET TN3270 Etoa Command Enables You to Display and ModifyASCII-to-EBCDIC and EBCDIC-to-ASCII Translation Tables SHOW/SET TN3270 Atoe Storage Requirements for TN3270 Definitions in Nvram TN3270 Commands That Free Nvram SpaceCommand Frees Nvram Space Used By Guidelines for Managing the Use of Nvram for TN3270 Local Define Port TN3270 Nvram Limit Limiting Nvram Usage Commands to Manage TN3270 Terminal Emulation TN3270 Access Server CharacteristicsCommand Description Default Description Default TN3270 Port Characteristics Displays Show CommandsPage Configuring and Managing Point-to-Point Protocol PPP Ports Enabling PPP on an Access Server Port Enabling PPP for Mixed TrafficExample Enabling PPP for Mixed Traffic Enabling Ports with Modems for PPP Enabling Dedicated PPP Traffic Using the Connect PPP Command Establishing and Ending a PPP SessionLocal Connect PPP Local Show Port 5 PPP LCP Characteristics Displaying PPP CharacteristicsDisplaying LCP Characteristics Example Displaying LCP Characteristics Field Description Values Default Fields in the LCP Characteristics Display Displaying Ipcp Characteristics Example Ipcp Characteristics Display Ipcp Characteristics Display FieldsIpcp Field Description Values Default Local Show Port 5 PPP Atcp Characteristics Atcp CharacteristicsExample Atcp Characteristics Display Atcp Characteristics Display Field Values Field Description Values Default Local Show Port 5 PPP LCP Status Displaying PPP StatusDisplaying LCP Status Example LCP Status Display Fields in the LCP Status Display Example Ipcp Status Display Displaying Ipcp Status Fields in the Ipcp Status Display Displaying Atcp Status Example Atcp Status DisplayLocal Show Port 5 PPP Atcp Status Fields in the Atcp Status Display Local Show Port 5 LCP Counters Example Commands to Display LCP CountersDisplaying PPP Counters Displaying LCP Counters Fields in the LCP Counters Display Displaying Ipcp Counters Example Command to Display the Ipcp Counters Fields in the Ipcp Counters DisplayLocal Show Port 5 Ipcp Counters Displaying Atcp Counters Example Command to Display the Atcp Counters Fields in the Atcp Counters DisplayLocal Show Port 5 Atcp Counters Field Description Chapter Managing IPX IPX Description Access Server Configuration Login Procedures Getting Started Checklist References Hardware and Software RequirementsSoftware Requirements Hardware Requirements Novell Utilities for Local Execution Setting Up Your PCPC Remote Access Software Novell Workstation Software Enabling IPX Setting Up the Network Access ServerConfiguring the Port for an Attached Device Local Change IPX Internal ipx-net Local Change IPX Enabled Configuring the Port for the Login Method Configuring the Port for Login to the Local PromptActivating PPP Configuring the Port Dedicated to PPP Configuring the Port for PPP/IPXCP Data LinkEnabling PPP/PAP Password Authentication Disabling PPP/PAP Password Authentication PasswordsLocal Change Port n LCP Authentication Disable SHOW/MONITOR Port n Description Summary of DECserver IPX Management CommandsPort PPP IPX Commands for LCP Port n LCP Display the values of the Ipxcp counters Port PPP IPX Commands for IpxcpPort PPP Commands for PPP Negotiation Status Port n Ipxcp Server IPX Commands CharacteristicsDisplay the values of the PPP counters Learn SNAP802 Modem Considerations Dial-In ModemsDial-Out PC Modems Recommended Serial Port Baud Rate Novell Operation Novell Client/Server Operation Novell Client/Server Operation Operational Checkout and Diagnosis Verifying Configuration Using the Define Command Local Define IPX DisabledDisabling IPX SAP802 Frame TypesStandard Ethernet RAW802 Local Show IPX Characteristics Displaying IPX CharacteristicsIPX Characteristics Display IPX Characteristics Display Fields Field Description Fields in the IPX Status Display Using the Show IPX CommandDisplaying IPX Status IPX Status Display IPX Counters Display Fields Use the Show IPX Counters commandDisplaying IPX Counters IPX Counters Display Field Description Field Description IPX Routes Display Fields Using the Show IPX Routes CommandDisplaying IPX Routes IPX Routes Display Option Description Resetting CountersUsing the Zero Command Zero Command OptionsPage Chapter Managing Dial Services Dial Services Command Groups Command GroupsEntering the SET Privileged command Server Configuration Display Checking the Current Server Settings Dialer String Descriptions String Type Default Value UsageDefining a Dialer Script Defining Dialer Script Strings Example Set Dialer Script Name Assigning the Dialer Script to a Port StepsDetermining the Current Dialer Script Example Defining the Dialer Script Example The Show Port Command DisplayDialer Script Generic14400 Preferred Service Callhome Assigning a Dialer Script to a Port Dialer Script Dickens Verifying Dialer Script ConfigurationExample Show New Port Configuration Local Change Port 2 Dialer Script dickens Local Show Port Showing the Current Dialer Service Characteristics Defining the Dialer Service Example Show Dialer Status Showing Dialer Service StatusExample Show Dialer, Port Security Enabled Local Show Dialer Attradeshow Characteristics Show Dialer Status Display Fields Status MeaningLocal Show Dialer Attradeshow Status Attradeshow Modifying the Dialer ServiceDisplaying Dialer Counters Example Show Dialer Counters Characteristic DescriptionComments Dialer Service CharacteristicsCharacteristic Description Comments User Account Characteristics Mode Command Variables UsernameMode Security Profile Information Configuring Interactive Dial RequestsConfiguring for Interactive Dial-Back Interactive Dial-Back Dial Service Example Framed Dial Requests Changing PPP Characteristics ExamplesConfiguring Dynamic Access Configuring Call-Back Framed Dial Requests Page ∙ Radius Chapter Managing Access Server Security Realm Definition Radius AuthorizationSecurity Type Descriptions Kerberos SecurID User AccountsStage Description Common Terminology Across Security Realms Security Server UDP PortsRadius Accounting Configuration Prerequisites Managing KerberosKerberos Host Requirements Case Sensitivity Configuration of User AuthenticationNetwork Access Server Requirements Configuring Kerberos Settings Example Definition of Kerberos Settings Local show kerb characteristics Displaying Kerberos SettingsPort Configuration Example Sample Show Port Command User Authentication Procedure Example Authentication with a Complete User NameUsername smith.su@finance.acme.com Password not echoed Alternative Password Command Changing a User Name and PasswordUser Authentication Counters Example Sample Kerberos User Authentication Session Local Zero Server Authentication Counters Port User Authentication CountersSetting the User Authentication Counters to Zero Local Show Port 1 Authentication Counters Minimal Setup for Radius Managing RadiusVariables Local Change Radius Interval seconds Optional Setup for RadiusLocal Change Radius Timeout seconds Example Including the Realm Name Number Radius User AuthorizationsExample Defining Realm Default Authorization Attributes Example Defining Password Authentication Type User Access to the Access Server Setting User PermissionsValue Description Additional Radius Attributes General Session AttributesGeneral Session Definition Attributes Framed Session Attributes Definition Framed Session Attributes Interactive session Definition Attributes Interactive Session Attributes Digital Vendor-Specific Attributes Radius General Non-Session AttributesRadius Overhead Definition Attributes Digital Vendor-Specific Attributes Radius Accounting Definition Attributes Radius Accounting Attributes Radius Optional Radius User Attributes SecurID Ports Using the Secret KeywordManaging SecurID SecurID Prompts SecurID Realms Minimal Setup for SecurIDOptional Setup for SecurID Local Change Securid Timeout seconds SecurID User Authorizations Noprivileged level of Decserver Local SET Server Realm JONAS.COM Managing Local Access Server SecurityExample Setting the Server Realm Defining the Realm Determining Security Configuration Displaying RADIUS, SECURID, and Kerberos CharacteristicsExample Showing Radius Characteristics Example Showing the Server Realm Example Showing SecurID Example Displaying Kerberos Characteristics Displaying Security SummaryExample Showing the Security Summary Showing Security Counters Showing the Authentication CountersShowing the User Port Authorization Profile Example Showing the User Port Authorization Profile Activating Autolink Example Configuring the Port Authentication Enabling Autolink AuthenticationSpecifying an Authentication Method Example Enabling Autolink Authentication Setting Autolink Timers Example Setting Autolink TimersChap Username Using a Login Script Timeouts LAT Protocol Requirement Specifying Other Security FeaturesSpecifying Dedicated Service for LAT or Telnet Resources Kerberos Requirement Local Change Port 5 Dedicated SALE.MKT.DEC.COM Specifying PasswordsLocal Change Port 5 Signal Control Enabled Telnet Requirement Local Change Port 5,6,7 Password Enabled Specifying Password LimitLogin Password Definition Example Local Change Server Login Password Total Example Changing the Server Password Attempt Limit Page Accounting Accounting Log File Accounting Description What Events Are Logged? Contents of Log Entry Types Event Field Descriptions Above Ping Autolink Local Access For nondedicated/preferred case, whatever you Session Disconnect Event The number of bytes of successfully When Events Are Logged Password Modified Events User Privilege Level Modified EventsSnmp Community Modified Events Managing Accounting Defining the Accounting Log SizeExample Defining the Accounting Log Size Example Changing the Accounting Console Changing the Accounting ThresholdChanging the Accounting Console Example Changing the Accounting Threshold Displaying Accounting Characteristics Example Displaying Accounting CharacteristicsLocal Show Accounting Characteristics Displaying the Accounting Log Example Displaying the Accounting LogLocal Show Accounting LOG LAT Remote View of the Accounting Log Using the Accounting Console Logging Feature # Telnet x.x.x.x 2001 ACCT.LOG Example Telnet Remote View of the Accounting Log57600 # Telnet x.x.x.x Appendix a Cable and Adapter Recommendations Cable and Adapter HardwareCable and Adapter Table Cable and Adapter Recommendations Glossary American Standard Code for Information Interchange AuthenticationAuthentication trap Bootptab file Broadcast BOOTP/TFTP ServerCircuit timer Command line recall and edit Data Set Ready Dedicated serviceCyclic Redundancy Check Datagram Downline loading DequeueDomain names Domain Name System Gateway Event loggingFailover Flow control Initialization Installation Verification ProcedureInternet Bootstrap Protocol Image Kerberos Keepalive timerInternet Protocol IP datagram LAT network LAT serviceLAT architecture LAT Control Program Local name server Local serviceMaintenance Operation Protocol Multicast timer Network Control Program Name resolutionNetwork access server Name server On-Demand Loading Font Protocol Nonvolatile Random Access MemoryPreferred service ODL Font Protocol Qualifier Random Access MemoryPrint spooler Privileged status Remote print queue ServiceService circuit-ID Service node Session management Service ratingService session Session Synchronous Switch charactersSubnet identifier Subnet mask Time To Live Terminal Device/Session Management ProtocolTerminal Server Manager Terminal session XON/XOFF characters User Datagram ProtocolVirtual circuit Wide Area Network Index Symbols Internet Host 7-13 Telnet Listener Broadcast Delete DSV$CONFIGURE 4-4,4-6Telnet Listener Cslip Index-4 IBM Index-6 Appletalk Characteristics 8-5 DSV$CONFIGURE Index-8 Index-9 BOOTP/TFTP Internet TCP Keepalive Retry Session Internet TCP Keepalive Timer 7-19 Port Port Session Status 11-27 Queue ALLAppletalk Status 8-5 Queue AppleTalk ARP display 8-14 AppleTalk routes display Index-14